Hi Stan, I've been selling Energy for 18 years now and remember those speakers. It's a very decent centre channel but will sound different than your C9. Major difference would be in the tweeter, the C9 use the aluminum dome but the EC200 uses a multi-laminate soft dome (from Peerless if memory serves). The aluminum dome sounds much more open and clear. Depends how picky you are about timbre matching but the closer the match, the more seamless the panning between the front three will be. The EFX are a dipole type of speaker and will again sound much different. They do quite a nice job on Pro-Logic but short change you on bass and detail for digital surround and multi-channel music. Again though, it depends how picky you will be about timbre matching. They certainly won't sound bad though (assuming they are in good working order).
Why not just pickup the current model C3 which is made to go with the larger Connoisseur series speakers? It's not frightfully expensive, and will match perfectly.
Same goes for the surround speakers. R1s, R3s. Your choice. You could get away with R1s in a smaller room, but the R3s are a derivative of the Veritas 2.0Rs, complete with the switch to change them from bi to dipole configuration.
Negotiate with your dealer. The centre channel is of paramount importance in movies, and in multichannel music, so it seems that that $200 would be wasted on an "interim solution" that is a few years old and that has very little resale value. You can pickup a C1 on eBay for ~$280 (I think there's one listed for around that). It's not the C3, and ideally, you'd want the C3, but the C1 might do. That's a better interim solution.
The AC300 is an awesome speaker, a classic now, and at $200.00 for a used one (in good shape of course) would be your best bet IMHO. I believe it would be a definite step up over all from the CC1. It's a biggin' though so measure to make sure you can accomodate it's size. I always liked those for stereo use in pairs too.