There are some serious ascetic considerations as well. My wife hates!!! speakers on stands (my JBL monitors are on top of a long low AV shelf) so that is one of the reasons I am going with floorstanding speakers. Also, nothing that is all black, garishly large or requires placement too far into the room.
1)Thiel 3.5I heard Thiels a long time ago and really liked these speakers then. Not sure what opinion I would have now after more experiences in audio to broaden my perspective. I beleive with these you need to sit a fair distance away from to get the drivers to sound cohesive, how much distance do you have from your mains?
2)av123 X-StatikFrom my experience with the OB7's which are also sealed similar design, these will feel anemic without a sub. If you are used to using a sub, you will definitely miss it here, and you are going to want one. However, this speaker is on sale now, in a woodgrain finish for only $700 a pair plus shipping. The kicker is that there is now a 30 day "you pay nothing" return policy.So you CAN hear them before you make your final decision. (But you will need most of that time just to get the caps in the crossover broken in) Also you are going to need a good bit >3ft or so of open space behind the baffles to make them work their magic on the OB midrange. How far out in the room can you go?
Also the open midrange is really something special. I don't think I can go back to traditional box speakers. When I try to listen to them now, I hear the boxyness right away and it turns me off. I don't know whether or not the boxed midrange is more accurate, but this openness is addicting!
When I first started to get out of mid-fi audio, I tried upgrading speakers first too. I wasn't too happy with just that change. I actually felt ripped off. Then when I got better amplification I realized I was blaming the speakers for falling short, when it wasn't their fault! So, when you get dual mono, or monoblock stereo amps, with a better pair of speakers, you will REALLY feel like you are getting somewhere...
If you can find a used ps audio c-100 (which is an integrated) try that. That thing really took my system up a couple of notches. If I was going to get monoblock amps (and I prob will down the road) I would get the wyred4sound stuff.
There is no magic bullet to doing this very inexpensively -at least that I have found yet. Although I would have saved a LOT of money if I would have found, and took the chance to try to build, the GR research kits first. I have some family that I would like to get them hooked up on the cheap, but this hobby is simply out of their price range.
I know this doesn't fit your case because you need a floorstander, but I was just thinking through something. GR research's new neo1x kit and world class servo controlled sub would only run someone about $1100 +shipping = 1) the kit 328, 2)using a parts express pre fab .5 (non-curved) cabinets 79*2, 3)and a servo sub driver 150, with 4)amp 270 and with a 5) rythmik's prefab box 200. The only woodworking bit was to cut the 3 holes in it, and drill out the screw holes, but you could rent the router from home depot, or probably even use a dremel or something!
Good luck.
Tony