It looks like a Klein Pulse Comp from 1998. The 1997 Comp is similar, but without suspension.
I have a 1997 Pulse Pro with a Marzocchi Z2 Ligth 98 fork and XT instead of gripshift. I bought everything new with that custom configuration in spring 1998. I had to fit a shorter stem, since I went for a Large (I was between M and L, went for longer reach/stack and shorter stem for better technical trail performance, but stand over hight can be a problem if you have short legs).
The frame is very stiff, so you'll need a plush Z2 or similar to make the ride softer. I also use low tire pressure, platform pedals and boots that make the ride softer. Max 3 hour rides are fine, longer is probably not so fun.