I didn't have to get the valves removed on my 8v head when I had it done about 3 weeks ago, - the valves are recessed into the head by about 15-20mm. Mine's a '90 model though- don't know if they are different. I Had to remove the camshaft though.
Skim cost me ?18. Pressure test was extra, but you'd probably only need that if it overheated or only blew/lost coolant when it was warmed up - cracks tend to expand with the heat apparently. ?150 isn't bad, but make sure they use genuine bits, especially for the gasket - if you want it to last. At that price they could well be cutting corners by giving you a pattern gasket costing about ?8 - I bought one of these and you can see the difference in quality.
What about doing the job yourself? Not too hard..
Cheers