Yes there's some good advice on that thread, especially from CG Trading.
As it's such a long thread just search 19 within it.
I run one of my lowered V6 GTVs on 225 40 18s(with arch liners in place) which was originally on 19s, on 235 35s, with FK coilovers & no arch liners but still rubbed at the rear. I fitted the wheels to another V6 GTV which had new std shocks all round....no real problem except on lock the fronts just touched the plastic arch liners.......especially if the ground was muddy with gravel sticking to the tyres. This was when I first started experimenting with GTV wheels etc & I didn't note the J or ET of the wheels, OZ Superleggera,.....wish I hadn't sold them now. I think they were 8 or 8.5J & ET -35?
The wheels mentioned by the OP in his 1st post would be right on the width clearance/rubbing limit for the rears on a V6**. If you fit 225 35s, instead of 235/35s, they're fractionally narrower to help clear the rear & slightly smaller diameter so should also clear the front easier.
**TSs(according to some Alfa handbooks, TS 1506mm V6 1530mm, & some knowledgeable people on here) have a slightly narrower rear track than the V6 so outward clearance should be easier. This may explain how some people with 17" Teledials can fit 15mm spacers at the rear & not have clearance problems while others do, TS vs V6?
Whatever you decide make sure your shocks, springs, bushes etc are all good & you have some bumpstops fitted. It's a bit of trial & error really but can be costly &/or annoying if you get it wrong. Remember also that new tyres will have deeper tread & therefore be closer to the bodywork etc.
This tyre size calculator might help: Tire size calculator
Pictured is my 18 front on lock showing plenty of clearance, the same car on OZ 19s & the GTV I sold them on.
So yes it can be done, good luck & look out for the pot holes.