Ubercart

They want to match the layout. That would mean a hard-coded catalog form, I think.

Here's a quick (somewhat simplified) description of their attendee registration (they have two other registration forms that would be similar in scope):

1. Get the primary registrant's name and addy, and that is one registration.
2. Get the names of others -- along with arrival and departure dates -- who'll be attending. Each name is an additional registration (i.e., product, or could be done as product attributes of the primary registration with options).
3. Get the # of vegetarian meals for the party.
4. If they're playing golf, get the names of the golfers (attributes, perhaps?) -- up to four golfers; each adds a cost.
...etc. They've got a bunch of fields, and the PDF isn't neat, but they want the online form to mimic it to reduce confusion. Their folks aren't big on computers, so using something (like a webform that could be used with inline fields and hooked through fillPDF or something similar?) that looks like the PDF is what they want.

I gave 'em a way to register last year using products and multi-buy, but when I had to update Ubercart it broke multibuy...so it got ugly, and I didn't notice (my own instance was apparently cached) so I didn't realize the hell they went thru. It got ugly. :/

I don't know enough about the forms API or Ubercart development to try to customize it myself, but I suspect the coding may not be too insane: every field on the PDF would be coded to the form, hopefully inline where needed and with an appropriate field size. If that's possible, then it may be plausible to use code from MultiBuy to add all to cart, and validation to count attributes (and adjust product price, where needed) in order to catch which fields were entered and which weren't.

There's also some logic that one of the forms would need -- if product "A" is chosen then disable "B" and "C" -- but again, I think that may not be too difficult if I could work with the developer and provide the logic and pseudocode.

It's a really big nationwide non-profit, so the successful implementation of the form would get some wide recognition, and I'd make sure that the coder (or coder's company?) would be added to the credits for making it happen.

Once the form was filled in and submitted to the cart, standard Ubercart would take over. (Tho ideally the cart wouldn't shift items to an ungrouped or out-of-order listing -- that happened mid-way through the last registration cycle, too, and I got lucky with an ad-hoc fix.)

Last year, their site was still css and frames; I just now got them to approve and move to Drupal. When I implemented their online registration last year, Drupal was simply the shell containing the Ubercart-based registration. This year, hopefully, they'll do more -- Drupal-side has been expanded and their old site removed. So far, they're happy....