You should be able to snag a 2nd hand EQ6 for around $1100, or get one new from Andrews Communication.
There are two main types of 'fits' to the mount.
One is called Vixen, one is referred to as Losmandy.
The newer EQ6 has a mount head that can take either, the older models tend to be one or the other.
You can buy an aftermarket 'puck' to upgrade the EQ6 to take either.
The telescope you buy may come with either or none.
You would want to pick up a telescope with mounting rings (that go around the telescope tube) and then a Vixen or Losmandy rail that bolts to the rings, then attaches to the mount head.
For that size scope, either a Vixen or Losmandy is fine, the Vixen is a skinnier lighter rail, the Losmandy more beefy, but neither will flex on a scope that size, so the choice is up to you.
These extras add up, which is why buying 2nd hand can be a great deal, the scope will often come with the rings and the rail.
In this image, the rings on the left are sitting on a vixen rail which then slides into the top of the mount.
http://firstlightoptics.com/user/con..._landscape.jpg