GAZ, Spax, AVO or Protech shocks?

[sonus]

My car currently has six (yes six) Spax coil over shocks with four of them with springs. I am looking into changing them for six new shocks with six springs to even up the loading on the rear suspension. The shocks will have to be 16" open. Length and approx. 10.5-11" closed length. Fronts will have 200-220lbs springs and the four rears will have 80-90lbs springs.

My car weighs approx 950kilos and has 48/52 weight distribution.

My questions are;

Can I get away with shocks for ID 1.9" springs? My reasoning would be that they are lighter in weight than larger hocks and springs.
Should I use steel or aluminum bodied shocks?
Do I need more than single adjustible for a road car?
Should I have custom valving done or will the shocks have enough adjustment to cover the spring weight span?
Spherical bearing or rubber mounts? The car is a fast road car used for fun rides and possibly the occational track day in the future.

Any other advice?

[mk2cossie]

Cant help with which brand to go for, but personally I'd go for spherical bearing mountings over bushes if you can.
The bushes normally end up squashed and deformed and end up hanging out of where they should be!

I would possibly go for aluminium bodies and in 1.9inch if you can get away with it, also possily look at dampers that can be mounted with the threaded body at the top of less unsprung weight as well

[sonus]

I did look at Penske shocks that are owner rebuildable and fit upside down, but they cost quite a bit more. I believe upside down shocks need to be gas filled or am I wrong in thinking this?

I am considering 1.9" shocks for the rear and keep the 2.25" for the fronts. According to some there might be a problem with coil bind for the desired length shock for the 1.9s whenusing 10" springs?

[scimjim]

Give them a call? I’ve had great help over the phone from all 3 of those companies (and have bought from all 3 for various cars) - also driven across to Spax and down to Protech and spoken to them in person (appreciate you can’t do that) but both extremely helpful and knowledgeable when discussing spring and damper requirements for road and track cars.

Spherical bearings can be a bit harsh on road cars with transmitted noise, the alloy protechs look great and stay clean. I have double adjustable Spax on a road car and have never touched them (fitted by the PO who is the tech director of Spax), single adjustable Spax on the car in my avatar which I adjust occasionally and single adjustable protechs on the sprint car which I adjust occasionally (with poly bushes as the roadgoing class regs require).