SLX is good stuff. That and the MT800 bottom bracket would be a solid setup. They're inexpensive and solid.

My personal preference is to go with Direct Mount chainrings with a zillion options for aftermarket but if you're going to stick with one setup, the Shimano is a great choice..

EDIT: If you go SLX, you'll need to do some homework on chainring size options. SLX is a MTB line...which is not a big problem but I'm guessing you've noticed the chainring sizing is very restricted to smaller sizes like 32, 34, 36T. You'll just need to source a ring that will accommodate the BCD of the spider. Because I didn't want to open that Pandora's Box on top of all the other upgrades I'm doing, I avoided the XT and XTR line that I might have considered.