There are a ton of variances in mounting styles, the majority of seats have a pretty simple 4-bolt mounting pattern, though some of the newer GM seats use a 2-bolt/2-hook mounting pattern. With most hod rods & project cars the easiest route to go with is a seat with a completely flat seat track. This allows you to through-bolt to the frame to ensure a safe, secure seat and reduces the amount of grinding you'll have to do.
Powered seats are great, but it's important to make sure you don't bite off more than you can chew. If you get a pair of "loaded" seats with heat, A/C, and memory you're going to be in for a rough ride. Powered tracks and lumbar are usually really easy, typically requiring just 12 volts and a ground.
Seats equipped with memory require a memory bypass. Theoretically this is done by mapping out the switch harness and splicing it into the wires that go directly to the track motors.
Seats equipped with heat (no A/C) can usually be wired in with the OEM heat switches and a little bit of fiddling. If you want a seat with heat but you can't find it, don't worry! You can simply add a universal heater to it. In the long run it will probably be cheaper and it will give you less headaches in wiring.
Seats equipped with heat/AC use a special system that requires a computer and that's not something you want to fiddle with. The best way to do it is to purchase a Katzkin DegreeZ kit from your local Katzkin dealer and retrofit it into your seat. For most manufacturers this is very easy as the DegreeZ system is used in the OEM system.
Larger Seats (Project Trucks)
Medium Seats for Hot Rods / Small Trucks