I'm looking for a company who can make a lot of changes and new functions in an x-cart webshop.

For the basic shop i want to use x-cart. ( i already have a licentie for x-cart pro and all of the modules on x-cart.com and for a lot of modules from other websites.)

Here i descripe the biggest changes and functions i need. Detaild functions i still work on but i want to get a idea of what this is going to cost.

Shops:
i have multiple shops what all have there own domainname and there own layout.
I want that all this shops work with the same admin system.
It is verry important that there are as less files as posible what need to be editted to make a new shop. Mabey best thing is to build shops true a good product feed??

What i want for this is a system where i can make each shop unique and do unique SEO optimalisation.
For this i want to fill in for each shop a different:

product description
product titel
product url
meta keywords
meta description
special offers
homepage products
and so on..

all this points are as wel for the products as the categories.
To have this each shop should have a own login like the provider area where all points of the shop can be modefyed.

Affiliate system:
The affiliate system is the place where webmasters can promote 1 or more of my shops and earn some commission.
Here it is important that i can make multiple groups of affiliates whit different kinds of commission.
Also it is important that not each product has the same commission. I need to select for eacht product i sell the amount of commission, for some products this will be 15% and for other 40% or somting between this.
The affiliate system should have the following functions:

promotion with banners
promotion with text links
banner roulating system (displaying another banner eacht time a visitor loads the page)
product feeds to build a own shop
deeplinks to products
promo info (extra info to a banner or link to see where a visitor/sale is comming from)
stats (here the affiliates can see what they have sold where it comes from and how mutch they have earned
affiliate newsletter

Resellers:
resellers are affiliates but this affiliates do not promote true banners or links but they download a small part of code what the place on there website and where they can change the collors and logo of the shop to there own style so the shop has there look and feel. The visitor can not see it works with my site becouse it is complete running on the domain of the reseller.
So not the complete software is on there site but just a small part of code (or working with an dns update). The commission and stats are the same as for the normal affiliates

Dropshipping system:
i also want to handel dropshipping orders. This mean other shops sell products and let me ship them out of there name.
The dropshippers pay me a wholesale price for products + a dropship commission + shipping cost.

For this alle products should have wholesale prices with groups. Drpshippers get a wholesale price and depending of how mutch they buy at my place they get a discount on this wholesale price.

Dropshippers should have a form where they can fill in the orders and send them to me.

Also i want automatich connection to my system.
There should be made some modules what can be inserted in other shopping cart systems like oscommerce of other systems and where the dropshipper have the posibilety to presse 1 button and direct sends that order into my system for shipping.
This orders come on a page where he can selects the orders he want to shiped by us and direct pay for the goods.

Complete managed shops:
this are shops just like hour own shops but now there is a login where the partner can see what all is happening in the shop and can answer custommer questions.
This partners do not have to do anything on the shop but only promote it and get commission for that. Payment is some higher than affiliate system but stats are the same.

Homeparty system:
I also organise homeparty's. The consulentes get a different commission as the affiliates but also in groups and for different products different kinds of commission.

I need for this a system where the consulentes can fill in all orders they have from the party's and where the commission they have earned is calculated.
Also custommer details should be samed and grouped by party en consulent date so they can be contacted for new party's

Wholesale:
also i need a wholesale system where custommers get wholesale prices and a discount depending of how mutch they buy.


All this functions are here now in big lines. Keep in mind that there are lots of small changes what i need in the software in this functions like:

changing of payment system (al payment options sepperated and withing the website)
categorie grouping
multiple order statussen
different kind of categorie selection for products ina admin
modefication of seo friendly urls
our productnummers and product nummbers and wholesale prices of wholesale company's (where i buy the products)
extra product fields
special analytics codes a special pages
and mutch more...
So when you gif me a price keep this in mind.
I'm looking for company's who now how x-cart is build and have multiple employees who can build togetter on this software.
The planning is to start this project in 2 to 4 months but already need some prices to see what it is going to cost.
Just reply now and i invite you when i place the real project to build.