the space sounds a bit small for a decent reverb space but certainly worth experimenting with.
You need as much hard/reflective surfaces as possible. Also as many odd angles so that you can break up the reverb field. You are looking for space to be as live as possible but you need to avoid standing waves. What I'd also recommend is a few sheets of slightly bent 4'x4' 12mm ply. Hang these randomly from the ceiling to break up the soundfield.
Also you need to be aiming for a reasonably flat response across the frequency domain.
Aim for as high a reverb time as possible - then if you want a different reverb effect you can throw in a few cushions to damp the room down a bit.
hope this helps, let us know how you get on.
PS - this thread might help
Reverb chambers back in the day