Speakers after GMA Europas

Used Thiel 3.5's and a used Threshold S 500.

I've gotta agree with Drubin, with the same reasons I offered my suggestion.

...And the Thiel's offer even more bass.:-)

Shakeydeal, Why would that make you laugh? Please remember the OP budget. Time and phase coherent sealed box, 89 dB, 4 Ohms nominal 4 Ohms minimum, 20Hz-20Khz +/- 2 dB. Please tell me of any other speakers any where near the asking used prices, that can offer similar performance. Heck, with the possible exception of the Vandy's, I think you'd be hard pressed to find anything today with similar performance at the price they were charging when new. You seem to dismiss bass rather haphazardly. While I'm not pretending that the speakers recommended offer the SPL levels that true subs will, perhaps you haven't seen the prices that people pay for subs and the frequency extension they provide? Would you consider any other components that deleted frequency response? I understand that some people's rooms can't accommodate such bass, and for them smaller speakers might be more appropriate. BTW, the Thiel 3.5's have different settings for such considerations.

Daimbert based upon your latest updates, I think you might be very happy with Vandersteens coupled with McCormack amplification. That combination should satify your sound quest, room and budget. Best of luck.

Rrog, the Thiels and the Vandersteens are some of the very few speakers that share similar design considerations with the GMA's the OP seemed to like so much. While not my first choice in power recommendations, both the Thiels and the Vandersteens can get by with 50 Watts in smaller rooms, but given the value these speakers offer, there is enough money left over for higher powered amplifiers. So far the OP has only suggested budget limitations, not room volume limitations. Even if there were in fact room volume limitations, subs would probably not be recommended. That your experience with Thiels and Vandersteens led you elsewhere doesn't negate the potential for the OP applications.

Another option might be Meadowlarks.

Rrog, Thiel recommends 50-250 Watts for the 3.5's, with the possibility that in some circumstances 25 or 300 Watts might be appropriate (8 Ohm load rating assuming ss w/ the ability to double down). Remember these Thiels don't drop below 4 Ohms. Vandersteen recommends 40-160 Watts (8 Ohm rating). Your point is well taken, the minimum recommendations will not play these speakers to their full potential, and are probably only suited for small rooms without big SPL expectations. Again the used cost of these speakers allows for the expense of more powerful amplification as might be needed.
Unlike the Thiels and Vandersteens there is no available support for the Meadowlarks, or for that matter Dunlavy's (which at this price point would only include models with less bass capability and yet more physical size).