what's everyone opinion on oil coolers?
526 wedge, street car. 4600lb wagon.
what would you go with? Tube and fin style or plate?
Also, what's the best adapter to use?

Stay away from Trans Dap because of quality issues. Canton offers stand alone parts that you can build what you want.Kits give some cheap and/or thick hoses that don't lend themselves to going around P/S and headers. Better to have the hoses made with AN fittings. Just stay away from 90* fittings. They can be restrictive.

The manufacturers want you to spend $ hundreds on braided line, which is superfluous at the pressures you will see. Hydraulic 2,000 psi hose (steel braid + rubber) is much cheaper, available pre-made in every size as surplus. Even 300 psi power steering hose is good, shops will make them for you in any config.
If I had to do this, I'd be using as much large diameter steel tubing as possible.
At least one fitting pointing up (preferably the exit).
Vibration mounts for the cooler.
Remember: heat only follows air flow which always goes from high pressure to low pressure. Your cooler efficiency is strongly affected by the front-to-back pressure differential, examining your ducting. If air can flow around the cooler it must be bigger. The hot air from the back will increase heat load to your radiator and ATF cooler.