I just use the same amp for my fretted, but i also like a really punchy/bright sound from my bass (punk style).
When I'm not using my AMP BH-420 (no longer available) my Ashdown MAG 400 sounds excellent through EA cabs. Not too shabby through my Eden D210XLTs either.
I tend to go direct these days. Laziness, mostly. I do think, though, that to cut through you need a bit more power for a fretless with flats than you do for the same bass fretted.
I'm still using my same amps - Crate BX-100 and an SWR Workingman's 10. Both sound even better than before I got my fretless. When I was in high school, we had a SWR California Blonde that we ran the acoustic bass through - that was truly an awesome sound to behold!
Carvin R600 head, biamped, highest frequencies boosted, mids boosted a tiny bit to bring out the mwah more, sub bass boosted, everything else cut a little bit. (kinda a "W" shape on the graphic eq) i send the highs to a 210+tweeter cab with the tweeter turned off, and the lows to a single 18. i like the way it sounds for jazz and latin stuff. good mwah, really nice tone, but not too loud. on the poweramp controls, i jack up the lows as far as i can without clipping, and then put in highs until i can hear them clearly. because of this i end up cutting the bass boost on my bass, and the mid as well. treble gets boosted a litltle bit. i set my balance about half way between the J/HB pickups, with the coil tap engaged on the HB pickup, and i blend in a tiny bit o the piezos. when i play in my rock band i hafta go full range and just crank it. i realize that because i boost some places adn cut elsewhere, im kinda cancelling out my own eqing, but trust me, it does make a difference. or at least i like to think so
I've heard that the Walter Woods amps are preferred by those who play stand-up basses, and jazz players who play stand-up and/or electric.