looking to get this 1999 yz250 (need advice)

So here are my thoughts:

My main concern is im a little worried about the suspension. I might need to gas up the rear shock and replace the fork springs and I'm afraid it might be expensive (or even worse, it might be blown.)

The reason that i think this is because it sits a few inches lower than it is suppose to and its pretty soft but there is no oil leaking from the forks or the rear shock.

So anyways, I would be the third owner and the first two pervious owners are a bit short (5'8") and weighing about 160lbs and i'm 5'10" weighing 210lbs.

So with that said, one of the theories i came up with was that this 1st owner repaced the link on the rear shock with a lowering link. (they make these things for crf250x)and put softer spring on the front and now it just needs oiling.

Does anyone know if the rear shock is a gas shock?

Also is the top end. The 1st owner rebuilt the top end before he sold it and this 2nd guy (the guy I'm buying it from) only rode if a few times and let it sit in his garage for 2yrs. Do you think I'd have to rebuild the top end anytime soon.

And one more thing Im actually trading my 2004 xr250 plus $125 (with blown forks bad breaks and wiring to the lights cut) for his 1999 yz250. What do you think about that?

Sorry I know I'm asking a whole bunch of questions but I really need to know.
Any advice is greatly appreciated. Thanks.