Hey John,
Are you wanting a Forms 2.0 form to submit to both your product database and Marketo? I haven't seen this working before. I'm not sure if it's possible to dual submit from a Forms 2.0, as opposed to fetching the data after submission from Marketo's database.
I can tell you what we do...can't speak to the Reachforce part because we don't use it though.
Our product's registration form is integrated with Marketo using the SOAP API and the
syncLead call. It's been a pain, to be honest, because you also have to do an associateLead munchkin call to attach the new record to the cookie and we've dealt with some race condition issues there.
If I could do it over I would explore the
server-side form post method. It does a much better job at replicating the functionality of a native form submit on the back-end and will submit to your product DB and Marketo. Note it is rate limited to 30 submissions per minute though.