[altq 1318] Is ALTQ right for me?

["Adam" <adam@ecamp.net>]

I administer a small network that is connected to the net via a Sprint
clear channel T1 line.  Some of the users of the T1 are day traders and
they require latency to be no more than 20-30ms.  Normally it is around
10.  If someone else on the network downloads a large file, they will
spike to 300+.  
I want to build a router that will give their IP addresses priority in
the queue, as they use very little bandwidth, but need the response
time.  Is this something ALTQ can do?  And if so, how?  Are their any
packages that do this sort of thing?  Everything I have read so far
seems to be much more complex than this.

Thanks
Adam