CiviCRM Community Forums (archive)

Hello CiviCRM community!
I am working on getting our non-profit's new webpage up and running. Because we're technically under the 501.c(3) umbrella of a university, we need to use their payment processor (plus it only charges 2%, so I am ok with this). The trick is this:
-Their system is set up so that various items (memberships, chapter dues, a donation item) are stored in their database
-I need to have a payment processor which will generate the URL for the 'Confirm' button that includes the IDs (on their end) of the items that the user is paying for - don't particularly need anything else.
-The IDs are likely to be different than any internal IDs in CiviCRM, so the code should be able to match them up.

I have two questions regarding this:
1. Is there a simple way to attach a field to objects that require payment (say, memberships and/or different items in price sets) to keep track of the external item IDs? I'd like to avoid having to keep a list in code, particularly for future site admins' peace of mind.
2. Is there a payment processor that works similarly to this that I could base code off of?

(Shadow third question: Is this the right forum for this post?)