Your suspension is not specific to your engine..... Any suspension from a rwd R33 will fit!
You own a Skyline, small fortunes are normal to fork out when things go wrong
Your shock may be able to be rebuilt by someone local, someone on here from around your area may know..... anyone?
If you cant find one exactly the same then yes you will have to buy a rear pair, you wont need to buy a set, it wont need to be GAB in the rear though
'Would it be better to just get a standard setup with lowering springs instead?'
I have no idea what you mean by 'better'.... Its still going to cost you money and you will sacrifice the quality ride good aftermarket suspension gives, factory shocks of that age are going to be well worn too so you may be up for a replacement factory shock soon after installing, its really a gamble! But its your money at the end of the day, none of us can tell you how to spend it
If I could I would tell you to spend it on me, I'd love a 25DET in my R32 please
For another option that may actually work out cheaper in the long run, why not go for a new set? I know some traders on here have very sharp deals!
Just a random question, how do ya find the GABs?
I was the first owner in NZ of my old R33 25t and it came from Japan on GAB coilovers, I loved them! The car stuck to the road like sh*t to a blanket (I have always loved that phrase lol) but they were stiff as hell too, quite bumpy on the local streets but on the open road it was awesome