Combining my sites into 1 entity

Its been awhile since Ive posted on here, but Ive been noticing a few changes... while Im still hoping for a few additions to marketpress and such I have noticed the big new addon since ive been gone... whmcs

Could you guys let me know if Im right in assuming this will work for what I want..... Basically from what Im reading I could use this to combine all my sites into 1 banner more or less

Basically I have a few sites atm that I run (though a few need work since Ive been away)
an ecommerce hosting service (multisite)
a gaming site
a politcal site

All have their own domains, and the ecommerce has a few domains, a large holdup I had there in selling domain names was the inability to automate that process, I have dreams of one day getting to the point of having too m any requests for me to handle on my own so im looking for as much automation as possible.

The Gaming Site is just that, a boring old gaming site for a friend, although I do host a mumble server there in addition to the wordpress on that domain

The Political site, is slowly taking off and getting donations but it has its own domain and is pretty simple

Now my question here, if I wanted to combine these all into 1 overall hosting provider say siteA.com where you could buy wordpress sites, and use whmcs for providing those could the sub sites be sites such as I already host?

Also... although im having some success I cant afford a dedicated yet so Im going VPS... so some concerns there are... can whmcs handle multiple vps servers?

I would love to be able to offer individuals there very own wordpress installation, or multisite installation I just am unsure as to what all this can offer so Im just trying to do my research before making my own master site to rule them all lol

Thanks