I think the first thing you should look at is your room. Will bipole/dipole speakers work there? If so, then what are your listening habits? If you mostly watch movies, then they would be a good fit. If you listen to a lot of multichannel music, then I think a speaker like the CB-10 would work better as surrounds. If you decide that a speaker like the CR-10 will work for you, I say jump on that deal because that's a good price for those.
Regarding your future plansif you are looking to upgrade your front L and R to a CF tower, I would recommend saving until you can afford the CF-70. I've owned most of the CB/CC/CF speakers, including the CF-30 and CF-70 and the CF-70 is a far superior speaker (of course it costs a lot more too) and to me, the difference in sound quality is worth the extra price. My only caveat with that is you should look to get the CF-70s when they go on salethey have been had for as little as $200/speaker within this past year. Energy has bumped their MSRP up, so the best price I've seen in the past 6 months on them was $275/speaker, which is still a good price IMO. I would not pay the standard $500+/speaker asking price for them.