Wise man to follow my advice and get the R8000 crank.
Bang for buck Shimano cranks throughout the product line have no peer in my experience.
Tens of thousands that run Wheels Mfg BB30 adapters to mount Shimano cranks...but many opt for a Praxis sleeve with good success as well. Some believe the sleeve is a bit more reliable because still advisable to Loctite BB30 bearings to the bike if running Whl Mfg spacers to mount your Ultegra crank.
Good choice and be sure to come back and give us a review as the R8000 crank is relatively new.
With Shimano crank, now what you need is a Stages powermeter which is perhaps the single best piece of kit to make you a better rider.