If you are really looking forward to start a BUSINESS... be a Reseller, but consider these factors:
1. Money - Always have some Capital to start, always have something in reserve.
2. Time - Do you have an allocated dedicated time for this?
3. Knowledge of hosting requirements, troubleshooting, etc....
4. Marketing - Do you know where to market your hosting services?
If not, just go on being an affiliate, its less much hassle