Boat type, size, weight, power etc...would help but in the interim, I've got an 18ft Malibu 182 (similar to Double Eagle 185) sitting on a EZLoader single axle with drums (which don't work well) and I would wish for the following:
1) galvanized
2) tandem axle
3) disc brakes
4) LED lighting
5) front rollers, rear bunks
In terms of where to buy, I'd find out what exaclty you want and call around. Best price wins!