Multiple domains - Should I use different registrars and hosting?

I am promoting keyword that are next to identical. I wanted to create multiple domains and sites for the same offer. Should I use different registrars and hosting accounts if I am going to work on ranking high?

Is there a cost effective way to manage the hosting as well as not spread it out on multiple servers?

What about HostGator Reseller account for hosting?

If you're going to crosslink/crosspromote, you'll be better off with different hosts. Shared hosting is cheap enough to spread things around.

Registrars aren't as important particularly if you're using one of the big ones, just keep the whois unique. I wouldn't use an unfamiliar registrar.

If the sites will be totally independent, doesn't matter much.