I'm not real sure what the question is, but I think you might be inquiring about brands to use when building a Pneumatic toy.
I have done a few of them and I like using chassis tech. They have been real good on price and good quality parts. The last time I used them however they messed up on my order. I'm hoping it was a 1 time thing. I think their web site is
www.airbagit.com
If they don't have what I'm looking for I'll use the thoerbeck bros. at
www.Suicidedoors.com.
If those 2 places don't have what your looking for your probably going to have to custom fab the parts.
This question probably belongs in the Lowered Suspension section if I had to guess.