I am using bobhosting.com although they dont have many servers left
Pretty good support, Not had many hitches, well actually only 1 and that was this morning...

if ya to speak with them, tell them bashys-place.com sent you :) dont know if i get out but ya never know lol

I'm in the market as well - very similar stats.... about 300-400 users on at a time.

about 1200-1400 posts a day

I would strongly recommend Tranquil Hosting. Mark will even move your forum for you. Prices are competitive, but nobody can touch his customer service. http://www.tqhosting.com/

<a href="http://1and1.com" target="_blank">http://1and1.com</a>

I've been using one of their servers for about 3 months now, and I am still quite impressed with the service. And the prices aren't bad for what they give.