In a dream home game room, a serious player would want both a 7' and a 9'..be able to practice on a table the same as the one he'll be on in an upcoming tourney.
Suggest you also view the how to select a table videos on you tube. Generally speaking, you get what you pay for. Veneered pressboard vs. solid wood, thickness of slate, quality of slate, and so on. It can become a pretty complicated subject.
The above video shows well why I'd hire pros. Not only do they know the tricks, they have specialized tools.
(edit) As long as were' on videos, check out this one about the pro-am Diamond. I know, broken record about diamonds, but they really are made better than others. This video should have one following giving you a factory tour, so you can actually see the materials used, how it's constructed.
https://www.youtube.com/watch?v=0vpLjMNhOSQ