How are they when your car is heavy loaded? Do they touch the inside of the wheelarches? I was afraid that with such low offset it would be a problem. And with spacers they are ever further out right? So a offset of 34 would probably work just fine? Or if it doesn't a 4-5 mm spacer will make it work?
Suspension kinematics brings the top of the wheels nicely inwards when under heavy load or crossing the bump (believe me, I am towing caravan as well). the remaining space in my case is enough that one could put fingers through (do not play that much with that, one never knows). I had to acount for this, otherwise I could not pass TÜV (MOT).
What thy normally do by while testing is to get the car of the ground and then put under diagonal wheels some blocks and then lower the car (to almost that car is only on those 2 wheels). this will bring on those wheels the suspension completely contracted, while opposite diagonal ones will be completely extracted. then they start turning the steering wheel to check
for any tough of wheel to arches.
check that you have at least 5 mm clearence between inner aide of the rim's spokes and the caliper of the brakes (more is better)
same applies between inner side of the wheel and the suspension
as said, if you have the right to return the goods (non damaged of course) within 2 weeks (think there is some EU law about that), even if you just changed your mind, use the opportunity and get those wheels. before you mount tire on the rims (which might prevent you of getting money back if not satisfied) check those clearances to calipers, suspension and see roughly how it would look like towards the arches
funny enough, at the rear axle you wont be needing most likely distancers if you use ET34 (I tried on mine ET30 and they were bringing tire dangerously close to arch), so I removed them. though, for my wintertire set, where I have original horseshue 8J18, 8"s could use some distancing at the back axle. on the front axle I keep distancers permanently.
for the bolts diameter correction from 108 or 112 mm to required 115 mm, use the adjustable bolts, I was using this type from this company
(please find yourself exactly which lenght you need)
last, but not the least, get the certificate of that rim that you want and check the static load that it can take, then compare that value with the half axis value of your car (of course, take the "heavier axle" vale). ideally, you'll find rims that are allready certified for your car. try maybe this web site
to see if you find directly something for your car. Funny enough, they have 3D model of 159, and if they have also 3D model of the desired rims, you could see good how it would look like.
I'm not going to buy a set of the 10 spoke TI wheels. I want something different.
seelction of what you want to put on your car is strictly your business mate. the most important thing is that you like them yourself mate! classic 10 spoke Ti wheels are gorgeous, but (from my perspective) we were all becoming too uniformed with them.