A few years back I transitioned to road(boring but a good workout) after a knee injury in hopes that I could rehab myself back into mountain biking and the impact that goes along with it. Fast forward to this winter and I have full use at the gym again and am participating in club sports with no side effects so I decided I wanted a bike for spring. My last bike was a 3x8 Sugar 3+. Looking for something a little more plush I found and purchased a 26" Slayer 70 with a Vanilla RLC fork...

It's not the latest and greatest but I'm testing the waters with this frame. I did the gear calculations from my old 11-28 20/32/42 and the options I've come up with after a little research are as follows:
SLX 1x10 with the 36T cassette and SLX brakes $195
SLX 1x10 with a modified 40T cassette and SLX Brakes $265
XT 1x11 with the 42T cassette and SLX/XT brakes $285/350

The area in question is MA/CT so some sand, some hardpack, rocks/roots, lots of rolling hills but elevation changes are moderate at best. Whichever I choose will be mated with a race face narrow wide 30/32T and I'm hoping will transition to a newer frameset after a few seasons if everything goes well. I'm not against a 2x but I'd really like to try 1x first and worst case I can put a small ring on my crank for a manual bail out gear until I add an FD. Even with road biking I'm skeptical that I could handle 11-36 with a 30T but I don't have much to go on so maybe I'm wrong. What do you guys think? Been out of the game for a minute so I'm looking for some insight.