Just done a bit of digging on the BBS website...
The 2 different sizes are either 19x8(ET44) or 19x8.5(ET45) - don't know where you're getting ET43 from, but the sizes and offsets I've got are straight from the BBS website. That said, what's 2mm between friends! https://bbs.com/pdfs/gutachten/Anwendungslisten/Anw_CIR.pdf
From looking on the "will they fit" website, the 8.5" wheels will poke 7.3mm more than the 8" wheels. My fronts (8.5" wide, ET46) are perfectly flush, so 1mm difference will make next to no difference on looks. https://www.willtheyfit.com/index.php?width=225&aspect=35&diameter=19&wheelwidth=8&offset=44&width2=235&aspect2=35&wheel_size=19&wheel_width=8-5&offset2=45 - you'd be able to compare your standard wheels to both sizes on this website too if that helps.
If it were me, I'd go for the 8.5" width with 235 tyres. I've had literally no issues with mine apart from having to do the fender screw mod, which takes about half an hour (I'm lowered too on Eibach sportlines).
I've had so many people mention how good the fitment is on mine. If you're anywhere near Lincoln, you're more than welcome to come have a look at mine to asses the fitment for yourself if you're still on the fence about it.
thanks for info and offer, i'm based herts/north london, but i am usually up in newark/grantham (pre lockdown). I had my car out today in main road, ruler / tape measures out, back and forth, think gonna settle for the 8J's ET44 - now and go 235/35 with PS4's - think this will be best and i know for certain i'll look good still.
haha it's mad tho, coz others will go, you're all talking just milimetrers, crazy tho how 1-2 make such a difference lol
the ET43 was coming up as selection on BBS Dealer rimstyle's website, just did a search google and also comes up with that offset - but now seems to advertiser different PCD
thanks everyone tho for assistance / info / help - sorry if been a nightmare. pics will be put up when all done