Sound Lab A-1's are, in my opinion, among the few speakers that are worthy successors to the excellent Martin Logan CLS's. Of course the fact that I'm a Sound Lab dealer does not in any way cloud or bias my opinion.... ;-]
For some movies, the subs would probably be a welcome addition. For music, it's unlikely you'd need 'em except maybe for organ and cannonfire. On normal music, the subs can probably add some headroom in the deep bass region if you listen very loud, but I only have one customers who uses subs with his full-sized Sound Labs.
The InnerSound 800's will certainly drive the Sound Labs well. Once again, the fact that I happen to peddle InnerSound amps does not in any way influence my opinion... ;-)
Depending on how those A-1's are outfitted, at some point down the road you can probably have some upgrades done to them which will make worthwhile improvements.
Best of luck to you!