Best floorstanding speakers less than $500

Don't sweat it. You can get that sound by choosing the right tubes for your amp. Go new Chinese or Russian, or NOS Amperex A-frames, or, maybe NOS German/Siemens and their ilk.
You, already, have an an amp that's not warm. It's "neutral". So, it shouldn't be very hard.
For example, new, reissued Tung Sols, etc.
Ask Kevin Deal at Upscale Audio. He'll set you up right.

The Wharfedales are very nice for the money.TSTO sells the 9.4 for $299.They also sell the Mordaunt Short MS-914 for less than $400.I have the 902 bookshelf version (in my wife's sitting room) and they look and sound great! The MS speakers do feature a bright,clear sound from their metal dome tweeters.

Whose TSTO?

It's now TSO Sound and Vision.Used to be The Stereo Trading Outlet(in Jenkintown,PA)

Check out the Energy speakers at less then 1/2 off and free shipping, these might fit your bill:

http://www.vanns.com/shop/servlet/item/reviews/542061916/energy-rc30-cherry