mid 2007 "best bang for the buck" hardware opinions

I saw an interesting topic in the archives on best bang for the buck for
$20k.. about a year old now.

So whats the thoughts on a current combined rack/disks/cpu combo around
the $10k-$15k point, currently?

I can configure up a Dell poweredge 2900 for $9k, but am wondering if
I'm missing out on something better.
( 9k spent with mr dell that gets you 2x quad core xeon X535s, so thats
8 cores total, with 24gb of memory
and 8x 146gb 15k serial attached scsi connected, raid10, attached to a
perc 5/i with redundant power supplies,
all in what looks like a 3u chassis). But the system is pretty maxxed
out like that, no room for future expansion.

better options? or a better balance for a pure db box that is mostly
smaller reads and large indexes?

This would be to go into a rack with existing but older equipment that
can be warm standby
so I don't have to split the cost here for getting redundancy.

thanks for any 2007 advice!