What pouch do those of you who have it use? I bought the med insert and a TT fight light mag pouch. It seems a little tight for the med tray to fit in. Any suggestions or recommendations for a "perfect" pouch?

The "perfect" pouch for that insert is the one is was designed around, the ATS mini upright GP pouch.  

The med insert will fit in a bunch of other random pouches but it's a touch too big to fit easily in a double M4 pouch.  I had one in a MBTR pouch I think before it just went into a side pocket of my pack.  

Fits great in an old ALICE triple 30rd mag pouch, if you don't mind going the ALICE/MOLLE adapter route.  I've had mine in a couple of double MOLLE M4 pouches, it fits better in some than others.  I've got a 3-color desert one that I had to swap a 4" Izzy bandage in place of the 6" one that I prefer in order to get it in, and even then it was pretty tight.  I've got another double M4 pouch in woodland that it goes into without too much effort, even with the 6" Izzy.