need amp advice

Another possibility might be to buy a good integrated 2 channel amp for the music and use a speaker switch to switch the two main speakers to run either off the Yamaha or off the integrated.

$1000 will buy a nice integrated .... Creek, Cyrus, Audiolab, Densen, Arcam, Adcom, even Rotel. Speaker switches run about $100. That way your main speakers can be used for both HT with the Yamaha in command and 2 channel music with the integrated at the helm.

Sorry ... it was an honest answer. I don't think the Yamaha will bring out the best in those speakers.
But I may be wrong (it's not uncommon !)
Is there any chance you could demo the various options ... if so then I'd do that. Take home a pre, a power and an integrated each costing around $1000 and see if any option is obviously better or worse than the others (noting that using both the $1000 pre and $1000 power is not an option since it blows your budget). I suspect that the question will then answer itself whether to get
1) New pre
2) New power
3) Integrated + speaker switch
4) Save it for the wedding.
Best of luck ... but don't take the dealer's advice without a home demo (or take your Yamaha to the dealer and listen to the Cambridge-Soliloquy setup at the dealer with various amps).

Hi Gunbunny, since you mention monitors on stands ... that would work very well if supplemented by a sub. For example a pair of LS3/5 on stands, plus a REL sub ... not much different in price to the Soliloquy I think and much higher WAF. I have Spica Angelus, so I know all about WAF !