I'm putting 2002 BMW 3 series convertible seats in my 66 fastback.
I will be driving my gal as much as possible and really wanted should belts but did not want to lose use of the back seat.
The mounting is a little tricky because you need to reinforce the floor ( being that all impact forces will be transferred to the mounting points, including the force of keeping your body planted int he seat in the event of an accident).
I will say the the wiring is cake if you don't care about the memory function on the seat. two wires per seat ( power and ground). They even have super fancy power headrest adjustments.
I had to look for a while, but i found a tan pair locally for $300 . I'm in the process of dying them black.