I was in EXACTLY the same situation as you... until today. Well almost, I’m totally new to hard booting, but felt pretty confident carving my various soft boot setups. I’m also in your weight range.
Decided to go all-in on a new setup with size 27 UPZ 12, SG Perf bindings, and the SG The Cult 169 board. This was all based on recommendations from the forum, shops, and the fact that I knew the Deeluxe 225s don’t fit width wise, even at a size up 28.
Since im a noob I don’t have any real wisdom to share other than some ininitial indoor observations:
The UPZ boots seem to fit true to size. I measured 27.5cm on both feet, and after heat molding, the Size 27 RC12s are still snug as hell.
The SG bindings seem great. The metal base plates look aerospase grade! Lift and can’t adjustment is limited to shims, and you only get one size. Not sure if that will be a problem moving forward, but most other bindings besides Catek are limited to shims too... so level playing field.
The SG board feels like a beast. I was worried I’d be on the far end of the weight range but it feels stiff as hell to me in hand so I’m sure it will be fine for fun carving. I went with the high end of their suggested binding angles at 45/38 at reference width, and could def go even lower angles if I want to.