I have had a pair of Quad 11Ls (which are a lovely finish and very wife-friendly) with the following Cyrus kit for a while now:
CDXT, DAC-X, Cyrus 8 integrated + X-Power
It sounds good, but the speakers are definitely the limiting factor in my set-up and Im about to replace them.
Dont go over-doing the electronics side of things as although the 21Ls are nice speakers and produce a very good sound with better electronics, I fear they may still be a limiting factor with some of the kit you've mentioned above.
If you spend decent amount on the new electronics, this will be apparant and you'll get the itch to upgrade the Quad's I bet, which judging by your posts you wont want to do!