10gbps peering subscriber switch recommendation

[nanog at data102.com (randal k)]

Good morning,
We're in the market to move our IX peering off of our core (too much
BGP/CPU :-/ ) and onto a dedicated switch.

Anybody have a recommendation on a switch that can do the following
without costing a fortune? I have scoured Cisco, and bang for the buck
is ... ASR9k (way over powered for handling zero-feature IX traffic),

3-8x 10gbps ports
64k routes minimum, preferably 128k
Must be able to speak BGP
Native/functional IPv6 would be sharp!
Basic QoS to police our ports

The prefix count seems to be the killer, as our exchange table is
getting pretty big (42k+ currently). I'm really tempted to build a
vyatta box or similar, but would rather do something off the shelf --
especially if it can be 1-2 gens old and cost effective.

I'm certain that this same situation is scratching many other folks as
exchanges become more important.

Thanks for your input in advance -- stay warm!
Randal