If you already have a machinist's level, I would say to give it a shot yourself. In the "Talk to a Mechanic" forum, there's a sticky post which is RKC's guide to leveling 3 piece slate tables. About 7-8 years ago I set up a 9 foot 3 piece slate table myself (My Avatar pic), and his guide worked like a charm. Just follow it to the letter and it will work out.
As far as cloth, believe it or not that's something you can do yourself as well. I have the official Simonis install DVD's that two of the forums best table mechanics (RKC and Jay) made years ago. They should still be available for about $20 each on Seybert's billiards website. There's a rail cloth & bed cloth install dvd. They cover both the staple down and glue down methods. I followed them with the staple method for the old table, and just did the glue down method on a 7' about a week ago. Both turned out great. The Simonis install DVD's will work for Simonis, as well as other similar worsted wool cloths.
I would suggest reading a bunch of threads in the talk to a mechanic section and going for it. It will add to the satisfaction you have playing on the table knowing you did it yourself.