Not sure that the Glasiar is the "future" as you say. Its been around for years! Id guess about the same time as the RV-6. But it is faster than the RV-6/7, although less room and less baggage space. But Ive only been in a Glasair II. The III might be better.
But also a lot more expensive. I wouldnt bother with the Questair Venture, very few seemed to get built, dont think they sell kits any more, it was Fast though!
If you want a really fast aircraft then look at the Akland Legend, or Team Rocket F1 Rocket, both outside the PFA's approval though.
Not sure how those guys manage to operate the N reg velocity over here. BUt one of them may have US citizenship, which would cetainly help. Operating N reg experimental aircraft outside the US is certainly not encouranged by the FAA and must be difficult, otherwise everyone would be doing it. There are very few N reg experimental aircraft in Europe and most of those that are here are owned by US citizens.
PS Another aircraft approved for Aerobatics and not spinning (in the UK anyway) is the Harvard/T-6