Marc, I don't have a set budget in mind. I guess under $1000 in parts (not including the crossover)?
I know I have an uphill battle and may forgo the sub idea altogether. Linkwitz's H-frames look interesting to me, and those Peerless subs aren't very expensive, so if it sucked I wouldn't be heart broken: http://www.linkwitzl...x-proto.htm#PW1
As for stereo vs mono, I was thinking about initially starting with 1 then maybe going for a pair if I wasn't satisfied. I haven't thought about the amps for them yet. Mostly trying to wrap my head around designs and the math.
I am definitely not doing this to get more boom, I want subs that "disappear". I don't even need a ton of extension... 35 Hz will be fine with me.