Engines, straight from the factory, were painted...except the bottom half of the crankcases. Don't ask why, don't know. Having said that, I have a brand new, never been used cylinder head, and to me...it looks painted!
There's a few differences between 'our' GSX's and 'their' GS's, mainly in the emissions dept. Physically, dimensions are the same. So, pipes will fit! Why not contact the supplier, and tell him your engine specs, and he'll advise you?
Got new stem made (longer than std. M). Harris supplied bearing, can't remember if it was top or bottom. Not special size bearing, Harris just ream out to match. In my case it was 52mm OD - 30mm ID @ £18 plus vat. That was 2006 price.
This is mine with 750M forks. Was going to fit ZX9R, but they were shorter again. Massive stanchions 'tho! Ignore the at tank,. Got rid or it ages ago for a Mag 4 one!
Thing is...I'm sure I have either an EFE of 1100 Teapot calliper somewhere! If I can find it, I'll offer it up to the B12 disc/hanger and see if it centres up.
If you've used heat already...the seals are toast! Continue with heat, and touch kids birthday cake candle to nipple threads. Wax (paraffin) will wick down the thread and free it off. Very rarely fails. In the unfortunate event you snap the bleed nipple off...all is not lost! Someone used to sell banjo bolts with a bleed nipple in the top. Can't remember who, 'tho! I would think anyone who supplies hoses/bolts?
I'd stick with the std. Suzuki plates if I was you. Really can't get better! Expensive...but worth it! I'd also keep the spacers alloy! Filing the slots in the drum, (within reason) is ok. Stack your plain plates in a pile to check for warpage.