I don't know too much about the hosting business, except that when I got my professional liability insurance, hosting was specifically listed as an "excluded" activity. Meaning that any suits arising from hosting activities were not covered - I assume this means liability for web hosts is greater than for consulting activities.
In any case, I think you should speak with an attorney or business consultant - spending a few hundred $$ on consulting time up front could save your assets (pun intended) down the road.
I would think you'd be steered to forming an S-corp - that form of business protects your personal assets better than the others.
But, as I said, you're best bet is to speak with an attorney.