PETG Hardline: EK-HDC or bitspower enhance multi-link? 12mm or 16mm?

I'm currently a soft tubing on barbs user. I'm looking into PETG Hardline for the first time and want to switch over when I get new hardware in the next couple months when ryzen and the 1080ti/Vega 10 stuff is all out. I've pretty much narrowed the fittings down to EK-HDC or bitspower enhance multi-link, both compression style. I'll consider others if someone has a suggestion for other good ones. The bitspower seem quite a bit more expensive, are they worth the price. They do have streamline 90 and 45 degree one piece fittings instead of adapters like ek which is nice. The adapter are fine but ek doesn't make color matching adapters which would still look fine I guess. Also not sure if to get 12mm or 16mm size with equivalent tubing. Also who makes the best fitting silicone bending tube insert?

I only have experience with Primochill PETG, their Revolver fittings, and their tube bending insert, but those components have worked very well for me - right at 2 years and no leaks, growth, or corrosion. Never even had a leak at start up. I didn't use any angled fittings as PETG is so easy to bend. I wasn't concerned over colors - I run just distilled water and (non-copper) PT Nuke PHN. Not any of the brands you mentioned, but I'm about to do a new build and am using the same things in this one.

I can't help on the 12mm / 16mm debate (I went with 14mm) but I have used the barrow silicone bending insert and it fit the ID of my tubes well. (https://smile.amazon.com/gp/product/B01M9CTRIN/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1) I also had good luck with their angle guides.

No matter what you do, don't waste your time on the crap XSPC peddles as a hard tubing bending kit. The included bending insert isn't silicone. Go ahead, mull that one over. It WILL melt to the inside of your tube on the first bend.

What size tubing would be best/easiest to work with in a 900d case?