Everything you need is available but the shipping will kill you.

Chassis Engineering makes motor and transmission mounts and they should ship for a reasonable amount. They also offer a bolt in Mustang II front crossmember and better springs for the rear.

I know there are not many places where you can get up to speed for any distance but the 700R4 is still a better choice. If your replacement rear end has low gears shifting into fourth will really save on gas and wear and tear on the engine (you will need to convert to an open drive line and your original rear end will not work.

There is nothing wrong with the old suspension but you will have a hard time getting the front end down. I have driven over some of your roads and I don't think you really want to cut any spring coils.

The small block Chevy swap is easy to do and will really pep up the old girl.

Good luck!!