Hi there...
here's what I'd offer within my bid.
First, all catalogs (appx. 13,000 items) must be converted to a web database (MySQL). Then the rest tasks can follow easily after the database prepared.
I'd arrange an admin panel where you can manage users (reps in this case) and also see their submitted reports (you can have it malied to you too if you want). Also, if the catalogs will be raised from time to time then I'll arrange a catalog section in admin panel where you can manage catalog items too.
The user (reps) will also have a login page where they can do as you want... the Web Form With Advanced Logic as you referred to.
Works assumed in 3 to max 10 days... actually the most time consuming I assumed will be the conversion from catalogs into MySQL database. Oh ya.. the works as explained above will be done in PHP. If you dont have a domain/hosting account then you can find least expensive domain/hosting provider that supports PHP & MySQL.
Now, so I can imagine it better, can you send excerpt of the catalogsfor me to check it first...
Let me know if you want to discuss further about it... Thanks.
- MEDY -