What speakers to Buy. Big Room -- Bookcase App.

Hello all. Thanks for the great board. I need help from those who know more about this than I. I just installed a McIntosh MX134 and MC206 Amp. They sound great and were well worth the $$$. I have a room about 22 X 18 and I have an Energy Veritas Center, a pair of Energy C6's for left and right and two energy RSS rear surrounds. My sub is a pinnacle baby boomer. The sound has improved tremendously over my previous pioneer elite receiver. However, the stero guy who installed it says my speakers need to be upgraged to get the "Full Benefit" of the McIntosh. They are pushing Revel M20's and C30 center or Dynaudio products together with a Rel sub. They say I'll hear about a 20% imporvement over what I have but that costs between $6k and $8k more. I listened to their speakers but frankly don't hear that big a difference to justify the $$$. Do you all have an opinion about what I should do or can you recommend other products that might work better for less or equal $$$. The one issue is that the front soundtage is mounted on shelves (the TV is built in to Cherry bookcases). Therefore, they say there are only a few speakers that will work well on bookcases and that the C6's are not made to be horizontally mounted as they are and that is what is limiting them.
Thoughts and suggestions are appreciated.

Happy thanksgiving one and all.

Whichever bookshelf speaker you choose it will generally sound much better on stands than on the bookcase. I had a pair of B&W CDM1 NTs on the shelves and the sound improved dramatically when I brought them forward with stands. If you really need to leave them there you will waste some of your $$$s. Although the M20s, if I remember correctly, have a setting for bookshelf mount.
The best way to kill the sound of a bookshelf speaker, is to put it on a bookshelf. I have the M 20s. They sing on killer stands. Put them on the Sistrum Mini Monitor Platforms, and you'll be in heaven. Put them on your bookshelves? forgeddabout it. They're over.
As a owner of the MX134 and a MC7205 (the five channel version of the 206) at 200 watters at 4 ohms I can recommend the Linn Katan a great sounding little bookshelf speaker and only about 900 hundred a pair. Another graet choice in a higher price range is the McIntosh L320 they are very impressive. You'love the Mc gear I just traded an MX132 in on the 134 and what a great peice of equipment.
Energy makes really great speakers for the money, they can compete with more expensive botique brands and really suprise you with their value. If you didn't hear a justifiable difference I would follow your instincts and just enjoy the great sound you now have, maybe upgrade your CD player/DVD player or dac if not done so alreadly, which may show a bigger return on your coins.
The M20s are fantastic. Get them on audiogon for cheaper and be done with it. Warrenh is correct that they sound better on the stands,but will still be better than the alternative on the bookshelf.
Thanks one and all for the advice. Very helpful.