Why not try with a 5.25'' seas excel? The w15cy
http://www.seas.no/index.php?option=com_content&task=view&id=62&Itemid=86We all know the quality of the seas excel. Also, the w15cy seems to have very low distortion down to 80hz:
http://www.htguide.com/forum/showthread.php4?t=28746 . So one could get very high spl with a sub crossed at 80hz.
About the tweeter, one could go with a mid priced fountek neocd 3.0.
If i may, i'd like to link this speaker:
http://www.xtz.se/produkt.php?allmant=true&produkt=30&eng=trueA review said they sound better than b&w 805S, yet they only cost 700 euros (something like 1000 dollars) per pair. And that's very low, considering they mout 6.5'' magnesium seas excel and fountek neocd 3.0. The only drivers cost about 500-550 euros.
To be honest i'd buy these if they sold a quite smaller version, that fits on my pc desk.
But with the w15cy, and even a sealed enclosure, one could get a smaller cabinet, yet a sorta flat frequency response down to 80hz.
The xtz 99.25 uses a 2nd order crossover, i think both for the woofer and the tweeter. Also, both the sealed cabined and the smaller woofer, would make it easier to get a flat frequency response; thus there would be no need for a back panel to change the frequency response of the tweeter, and no need to put the speakers far from the wall, not to get too boomy bass.
Jsalk could also give the possibility to choose for other veneers ^^.
Also, with such good speakers, a t-amp would have too little quality. But with a relatively cheap price one could get a much better (and powerful) class D amplifier:
http://store.virtueaudio.com/SearchResults.asp?Cat=26So sensitivity isn't really an issue.