We use Motorola rackmounts. Very pricy, but very robust - you indeed
get what you pay for. We haven't had a problem to speak of with these.
It's nice not to have to worry about them.
I'm not at the office now and don't remember the exact name of the
cards we use (I think it's 3262 but not positive). They come on
cards with 2 V.34 modems each... the chassis+backplane was around $3800,
and each dual-modem card is about $975. The chassis supports 21 cards
and has redundant power supplies. All network manageable.
If you want/need more info let me know --
David Ramsey
System Administrator
Charlotte's Web
dmr@charweb.org