I actually got my own little ghetto HLTV server running yesterday, to see what all it involved. I also did some digging on the internet. http://www.hltv.org/read.asp?id=247 as well as the file on my computer called hltv-readme.txt very informative.
I had no idea it meant a whole new computer and IP, however Ulkesh's "run it on the same machine" idea is what I was thinking would also work. A dedicated HLTV server on a T3 line can hold up to 255 viewers. on DSL, can hold 20. I dunno the speed of the armoury, sorry. If the server is split between an HL game and an HLTV proxy, assuming 25 players max plus 1 slot for the HLTV, the HLTV can handle 10 viewers (T3 line).
There's some numbers for you, Gator.
I had no idea it actually took so much. Silly Klif. Of course, I could always just set up my ghetto-HLTV proxy into the armoury when I'm not at home (with permission, of course).
the HLTV fileS come with half-life. Click the link above, it'll tell you which are necessary. They should be in the same directory as your HL.exe file.