Rear IRS Suspension Question

[fastbacker]

OK. So I think I'm going to look for some wide track aluminum 944 rear arms and brakes (along with t-bars, spring plates and axles). The information out there is a little confusing as it seems there are different versions of the same width arms (?). I did come up with this info on aluminum arms via some searching:

U.S. Models:
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86-89 944 S
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86-89 944 Turbo
89-91 944 S2
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89 944 Turbo S
90-91 944 Turbo
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Will all these options work to widen the track by 3" per side. Are all the brakes used the same? All things being equal (if so), are some more easily obtainable?
Any pros and cons in comparisons?

Thanks-
Craig