Help.

I need advice with a planned upgrade. Anyone that has experience with
these components, especially if they were used together, please let me
know what you think. All thoughts or advice greatly appreciated!!

Listening Room:
15' x 21' with sloping ceiling from 9' to 15', speakers on the 9' side,
three large openings to other rooms, carpet, minimal furniture. Two of
the large opening on the back wall.

Current System:
NAD 314 integrated amp
Parasound C/DP 1000 CD player
Klipsch Cornwall I speakers
Velodyne DLS 4000 subwoofer

Current Impression:
Lacks dynamics. Light mid bass response on most recordings, seems to
lack punch. Music that is very busy sounds somewhat muddy. You must
concentrate to see the sound stage. Upper end can have slight edge, but
not bad overall.

Planned Purchases:

I was thinking of dumping the NAD and purchasing a Bryston 3B or 4B NRB
or ST amp. The preamp that I had in mind was the Audio Research LS3 or
LP9MKII. How would these components play together? Which pre would
better suit the Bryston? How would the whole thing match the Klipsch?
Am I on the right track? What about the room, do I need another subwoofer?

Thanks for all reply's !!