If you have to position your speakers that close to the front wall you will definitely need room treatments behind the speakers.
I'd say it depends, because if my experience is any indication, the speakers should work perfectly well in your room. My Timepieces have barely 18" behind them, maybe less, and they sound fantastic.
I'll eventually have Revelations, and they'll be placed in the same position as the Timepieces. If I had any doubt whatsoever about their ability to perform well there, I'd have never spent the $$$.
As for performance of the speaker itself, you'll get what you feed it. SP Techs are known for their tight, realistic-sounding bass, and they are *NOT* known for etched or otherwise uncomfortable highs. They should perform quite well with your equipment.
However, SP Tech speakers have their roots in pro audio, and consequently they are very revealing. They may be to your liking, but it sounds as though you may want a warm, forgiving speaker. SP Techs are as clean, clear and neutral as I've heard, so they may not be what you're looking for.
Nice ICs, BTW. I have a couple pair and have no intention of parting with them.
The Continuums will be more realistic (better dynamics, etc.) but the TP's will simply be one volume notch and frequency extreme less...
Actually the reverse is true for frequency extremes as the Timepieces go a little deeper than the Continuums, but dynamics and distortion are slightly better with the 3-driver speakers.