C-Forum

I have a good friend I have paddled tandem with on easier whitewater. We are thinking tandem in harder stuff might be fun but do not have a boat appropriate for that. We are thinking about a 3-5 day clinic to give us access to some better performing boats and get some technique input.
We are both experienced C1/OC1 class IV boaters, we are just looking to try something new. We are in the mid Atlantic area. Any suggestions as to where we might go with this?

Maybe some slalom oc2/c2 training would be a good start to focus on getting coordinated together? A large part of c2 is communication and coordination with your partner, and slalom would be a viable way to get that and maybe a readier way to find instruction than for oc2 cruising. You should be able to find some slalom c2 training around DC I'd think.

Splurge on a 5 day workshop at Madawaska Kanu Centre (no affiliation, just a satisfied customer). They have a decent fleet of rental boats.

I second that, but it would be a long trip from Costa Rica if that's where you are. I go every year and the folks there are the best. Paddle all day, walk up from the river then hit the sauna and drink beers on the patio in the evening. It's a great way to spend a vacation even if it's not the CIV you're used to.

Go with a C2. An OC2 ships a lot of water and becomes difficult to handle in more serious water. A C2 would probably be more maneuverable, is a hole-punching machine and is easier to roll. One place to check out is Nantahala Outdoor Center in western North Carolina for lessons. I got C2 lessons there once upon a time.
I hope you can make it happen. There is nothing more exciting to watch on the river than a coordinated C2 team