Wheels - width and offset question!

I brought a set of genuine 19" speedlines advertised as 8.5j et48 with 235/45/19 tyres, of which two were at the legal limit.

I picked them up, checked that they weren't bent or cracked stuck them in the car and got home and put them straight in the garage.

FFWD to last night when I thought I would double check the width and offset before ordering a set of spacers ready to get the wheels centres painted and found that they are actually a 19x9j et33 wheel with 255/40/19 tyres.

My car is an 06 Quattro Saloon (3.2 if that makes a difference) S-Line so the questions are

I know that et33 should work, but with the width being 9" is that too much?
assuing that the rim width and offset work what size tyre do I need?

Thanks in advance!

Simon

just edited my post to say the current tyres on the wheels are 255/40 not 225!

oh and at the moment I am on standard S-line suspension, possibly going to change to the b5 perch at the front but I swore I wouldn't modify this one....

I'm in Cinderhill, no plans to go to ADI.

My last modifying outing cost me the best part of £20k and and ended up with a 450bhp RWD monster and three written off cars! This Audi is supposed to be my sensible choice while I save up for an Aston (or a Nissan GTR)