Yeah, weight matters a lot on a mountain bike. The fuel should have air suspension fr and rr, so it will be tuneable for rider weight. You will need a little more than average, but still well within the normal tuning range. Ask your shop about a shock pump. It is like a tire pump, but is designed for tuning air shocks. Very low volume/high pressure pump.
Warning-if you don't know what you are doing, you should ask the shop to help you with an initial "ballpark" set-up. The problem is, many shop employees don't really know much about how to set things up the right way. You might luck out and have a good one, but too many are just salesmen. If in doubt, ask if the shop's mechanic is around-that may be your best bet. (Sorry, but I have two buds who recently bought bikes from two different shops and neither bike had spring rate even close, I have also test ridden bikes at other shops where salesmen had no idea how to set up for my weight)
From your initial set-up, use the shock pump to play with settings 5-10 psi up or down and try to find your ideal settings. Just sitting on the bike should give somewhere around 25% sag.
As you figure out what pressures you like fr and rr, write them down someplace safe so that after sitting for a long period (winter) you can quickly get things back to where they should be if you have lost a little pressure.
