Full-Race, I think offers theres in 2 sizes: 20" x 8" x 3" or
20" x 11" x 3" and use PWR or Garret tube and fin cores
Spearco, has intercoolers that range in size (the size of the core and from endtank to endtank) and flow rate. I'm using a Spearco intercooler but I had to hack my front bumper a bit.
PWR, you'll have to check on the sizes they offer.
GReddy offers the Type 24 and Type 31 intercoolers, I forget which one is bigger but I think it's the Type 31.
Apex'i, I'm not really sure you'll have to check up on that one also as well as the HKS.
As for best bang for your buck I would look into one of these 3: Full-Race, Spearco and PWR. Do a little research though see what other people think as well, these are just my opinions. Also some cores/fins are different in some intercoolers than others.