Separate back-office application extends PrestaShop

[Trampino]

Dear PrestaShop experts,
I am looking for developer, who has good knowledge of PrestaShop php code and mainly PrestaShop database for version 1.6.X.
I need to develope php application with own GUI, which will use PrestaShop database.

Application will mainly have following functions:
Create and edit PrestaShop supplier.
Login to/Logout from application (based on extended supplier's data structure in PrestaShop database)
Create and edit PrestaShop product. (including: upload of virtual product file, connect product with specified cattegories in product category tree, connect product with concrete supplier, set product price).

I have complete specification of application behavior, including detail CSS and HTML prototype. I prefer CZECH or SLOVAK developers, but it is not restriction and I have not problem translate my specification to english.  

If it is interesting for you, pleas write me shortly about your expiriences and references and write me your base time and price estimate for such application.

Thanks a lot for your response.