Is it possible for you to fund the Klipsch RP-260F or 280F purchase before you sell the B&W 804's? If so, then do that and do a head to head.
Emig, you can get an idea of prices by looking at Hifi Shark's sold listings.
As far as speakers, I have heard B&W's and like their sound. The Klipsh are loved by many, though I haven't listened to them since the 70's and they were the huge Cornwall's or something like that. They are nice, but I don't think will give you the detail of the B&W's.
If you want to get something 'better', I suggest a time an phase aligned speaker like Vandersteen.
Magnepan, ProAc, and Harbeth are some other manufacturers I would recommend you listen to before buying anything. Of course, try to find a place that sells the Klipsh, or maybe a local Agon'er, and see if they suit you.
i would see what trades you could do with The Music Room in Colorado, great fantastic Audiogon dealer.....
other than loud you would IMO be selling yourself short....
and yes for the K fans i have a pair of vintage 74 Cornwalls rebuilt....in the garage.....possibly the only thing i own capable of drowning out a fine german flat six on full rpm song....
maybe tge Stihl.....?