I have 2 SB engined 1.6 GTD's, on both the throttle damper just squelches and slides in and out with little resistance.
I found two little brand new gas lifter struts the same size that fit at work, its like a tiny boot lifter strut.
Whats it for, do I need it? and is it ok to use gas struts instead of oil? ones

Damper is part 11 in diagram
You don't need it. AFAIK, it's something to do with the pollution control system, and won't affest the way your car runs.
2X... not needed....one of the first things I pitch when I'm tidying up the engine compartment.

Come to think of it... I don't think I've ever seen one that offers any real resistance to closing.