I have decided to keep the air! I haven't decided which company to go with yet, but I am replacing everything. I also am replacing all other suspension parts. Are there any poly suspension parts out there or will I have to buy a poly kit and remove the bushings off new parts?

Go with American Air.

You will have to swap poly bushing into the new parts.

Look for parts for the '96 Thunderbird LX V8 when looking for suspension parts (other than the upper control arm and the air springs).

If you find a poly suspension kit, it'll be for a Thunderbird.