You may know how to set up a web server etc but I think you could find it too much work in time and too much stress. What if the hits of one site becomes too great for the server (and your upload speed)? What if you have to start using clustered or load balanced servers because the site is getting so busy?
In my experience the best set up server will always have issues (hardware and software) from time to time and you will have to fix them (even at 11pm at night when all you want to do is go to bed!). Got spare hard drives? Taking daily backups? etc.
My team of poeple (which includes myself) is a very capbable one - but I am not going to host my own web servers for a long time yet.
As for an alternative, I have been a customer of Fasthosts as a reseller for many years now (about 6-8 years I think) and I have had a few minor problems and one or two major ones. All of which have been resolved. Fasthosts do NOT impose bandwitdh limitations and if you have the reseller abccout then you have unlimited everything (email addresses on each domain, disk space on the domain etc). EDIT: 'Unlimited' includes unlimited domains of course.
The reseller account costs me £600 per year - I have around 50+ domains on the account now so it pays ofr itself.
The link is:
http://www.fasthosts.co.uk/resellers/
Hope you get things sorted matey :-)