I used to have the Moog LPF and it was crazy as hell, but it made my entire rig sound like absolute crap. I guess the previous owner messed with the guts and I ended up selling it for more than I paid for it to someone who wanted broken pedals.
The Digitech Synth Wah produces a few sounds I can deal with, but yeah, I guess that kind of impractical is not a good thing, haha.
LPF? The rackmount Peavey Spectrum-it has both a full featured envelop generator and the LPF in one box, plus midi control!
If you want bandpass and high pass, then you've got to go with something else, a modular synth approach would be pretty cool. Or misuse something like the Studio Electronics SE1x with outboard triggering and midi control from the Moog CF201 pedal...
I have a Prometheus, cool pedal with lots of options.
It might not be as wild as you're looking for though, I'd think.
I'd like to try one of those Iron Ether myself, they sound wicked.
I also have a TWA Little Dipper. Closer to a Mutron, apparently.
They are discontinued, so look used. Not cheap when new either.
You get more of a vocal filter going on, much different from most I've tried.
+1 on Prometheus it has a CRAP ton of sounds on it, and some really random and far out stuff on it. If you like twisting knobs, this one will keep you busy for a while. Full disclosure - I have on on offer in the Emporium (I think I'm the "local guy" you are talking about - I have it on craigslist too) for relatively short dough (or trade), if you are interested in giving it a spin. It's a really fun pedal, just way too much for my meager filtering needs.