Welcome! How much do you want to spend? What do you need in the way of features/connectivity in the avr otherwise?
Might look around accessories4less.com for discount/refurb avrs, maybe look at the Denon X1400 for the lower price range, X3400 or above if you have a larger budget.
You want to use the XL7s as heights or wides? Or do you want to use the CVs and Fluances as separate L/R speaker sets? My avr can handle such dual L/R setups, one for surround, one for just 2ch. If you use heights/wides up front with L/R/C, and want to use the Bose for surrounds, that would be a 7ch system so not sure which way you're thinking here.