Speakers after GMA Europas

Personally I would pass on the Thiels and Vandersteen speakers. Been there done that. Adjustments or not, the Thiels need at least a medium size room and so do Vandersteens. Not to mention the power requirement of the Thiels whereas many high quality monitors are happy with 50 watts. Want more bass from your mini monitors? Get a subwoofer.

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.

Unsound, Except size and neither the Thiels or Vandersteens are going to play at anywhere near their potential with a 50 watt amplifier.

Meadowlarks are a great recommendation.

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).