Enhancements to an Existing Sales Quotation Software (Version 2)

I have a properly designed and fully functional Sales Quotation software. This software helps in preparing Sales Quotations for the prospective customers who come to my retail outlet (I am a faucet and sanitary ware trader). This software is presently designed for the product database of a single manufacturer. Product database is in the form of MS Excel file and is pretty simple in itself with basic fields such as Sales Price, Purchase Price, Serial Number, Image etc. This software has been designed using Java, with JavaFX on front end. I have the source code which is pretty neat, properly commented and written in a standard manner. I have attached the screenshots of the input screen while preparing a Sales Quote and some sample Sales Quotations i.e. the Output of the software. Now, I want add the product database of other manufacturers to this software. The product database of most of these manufacturers is same with the common basic fields as previously mentioned and some might have a couple of additional price fields also. There will only be slight changes in the existing design so as to incorporate the option of selecting the products of other manufacturers. I am looking an individual/company who can incorporate these changes in the existing software (i.e. include new product databases and some design tweaks), test it properly and provide a bug free finished software.