Want to set up web hosting, but not quite sure how to go about it.

I have an advertising company and for the past several years I've setup a hosting account for each web client and then designed and hosted their website on that one account. Needless to say I now have some 30+ odd logins for each client's hosting account (shared hosting: GoDaddy, Bluehost, HostGator).

I'm looking for a better way of doing things going forward. Would it be better to do a reseller hosting (like through HostGator) and provision an account for each website?

OR

Setup a multisite installation and use subdomain to work on the site then map the domain to it once the site is ready to go live?

What do you do?