Congrats on your upgrade!
Indeed its just a good start oppman. Having the 10's on rear was not considered before. Do you think it is better than having a pair of ADP's there? But if ever the 60's become available here, then that would be my choice over the 100's. It's too early to tell though. Another upgrade is having an amp first. An Emotiva perhaps if i could get one here.
I wasn't thinking. 10's vs ADP's depends on your room setup. Because of window placement and a wall cutout between the living room and dining room ADP's aren't really an option for my theater system. They would have to be mounted at ceiling level. I'd have to go with 10's or 20's. If your room will accomodate ADP's they might be a good choice. I've read opposing opinions, so I think it's one of those personal preference issues. If you ever get 60's or 100's, then moving the 20's to the back makes sense from a $ standpoint. I'm pretty confident you will be pleased with the 20's for a while.
If you decide to go with an external amp later, I think you will be pleased with Emotiva. I love mine. I'd just like to trade my XPA-2 for an XPA-5 instead of running the center/rears off the AVR. If I had the rack space, I'd just add an XPA-3. This will definately have to wait though.
My upgrade bug was costly. S8's in maple will be replacing my S2's. The good part is that I will be done buying speakers for a very long time. I just got tired of incremental improvements and the hassle of selling and shipping what I was replacing. I went from Klipsch towers to Paradigm Studio 100's to Signature S2's and now to the S8's. Spending more now probably will save me money in the future (I hope).