Im looking for RubyOnRails Hosting, but with many sides.

Im looking for some RubyOnRails Hosting.

but: i will seperate the domainregistry and the hosting.

i want to point one or many domains to this hosting without to
register the domains with the hosting company. i will only point the
dns A or CNAME record to the hosting.

witch feature i need for this?
witch hoster can serve this?

thanks.

PS:
my current hoster D*mainf*ctory don't support RoR and not allow
"external" domains.

You might want to check out dreamhost.com

thanks for the suggestion.

i see in the documents i can add more domains to my dreamhost account
with only changing the dns to the dreamhost dns.

i plan later to display content depending on the domain - but with one
script

but:
a) is there at dreamhost a api for adding more domains to my account
with a script (not manualy)?
b) can i add a wildcard domain to dreamhost, so that i dont need to
configure each domain? (maybe i need a seperate ip for this?)