Jeff, I have been thinking of trying the same thing (2 bucket subs, 75-100 W plate amps) for my FH3s.
Currently I use Dayton's 100 W plate amp to run a single 8" sub in my office with a SEX 2.1 wired as Paul suggests. It is decent but inefficient 4 Ohm sub, designed for car stereo, in a small sealed enclosure. The 100 W plate is running almost wide open to blend with the little single driver micro-fonkens, and I'm no bass-head. Just my experience, a more efficient driver in a larger enclosure would no doubt help.
I've poured over the various write-ups, even the nay-sayers, about the bucket sub, and it seems like a no brainer to give it a try for the modest investment. (2 subs + 2 amps)