Web Form With Advanced Logic Needed

I need a web form created for a team of sales reps that have varying levels of sophistication when it comes to using technology. The form would need to be very user friendly but have logic built in to help prevent them from making errors. I’m hoping you could offer suggestions on how this form could be built and then quote me on it. Our company has five different catalogs (appx. 13,000 items) that we sell out of on a consignment program with our largest customer. It is the job of the reps to go into these stores, count product, and report those counts back to headquarters. The issue is they are reporting the information back in so many different types of formats that it’s impossible for us to manage. Ideally I’d like for the rep to be able to select the store they are submitting a count for from a drop down list (there are between 600-700 locations). From there I’d like for there to be an entry box where they can enter an item number. There needs to be some kind of logic in place to check the item number they enter against our catalog so that they/we can be sure they are submitting valid item numbers. From there they would enter the count and continue that process until they have entered all the items that they counted. Upon submission of the form I’d like it to either e-mail us an Excel spreadsheet with the information sorted as shown in the attachment. Please let me know if this is possible or if you have any ideas to improve this process. If it can be done please let me know what the cost would be and how long it would take to complete.