Remote SQL host - Help plz!

So here is what I need. I need a host that will allow me to setup and use a sql database remotely.

As an example I have sites on various servers many platforms, like wordpress as an example. I want to be able to set up the site on my current server to use the sql database on another host, so I need rights where it can write to and call this database.

Anyone run/use a host that they will recommend which I can host some databases on for use with sites not hosted with them? I have 3 different hosts right now and all allow LIMITED remote sql which is for testing, etc. ONLY but all say it is against their TOS to set up an actual site, which is hosted somewhere else, and have it remotely use a database hosted with them. Much thanks in advance!

As a part of one of the services I offer to clients I'd like to be able to let them control the sites and domains on their host but I need to be able to keep all of the databases (used for setup and various maintenance) on a central server/host that is mine and not theirs. From a technical standpoint its straightforward I believe, just switch out localhost for the IP where I will host the databases and everything else should work just fine. I just can't find a host that wants to let me do it

Amazon's RDS is apparently good and certainly widely used hosted MySQL service.

The thing I dislike about their cloud services though is the lack of "pre-defined" pricing. Charges are based upon several variables (mostly pertaining to resource consumption in some way).

I had a look at a couple of other hosted MySQL services, but most of them seem less than desirable as their footers still read "2011".