I have a 140mm hardtail from 2015 with pretty similar geo and it really doesn't hold me back compared to my newer a bit more updated full squish. These 1x upgrades really aren't much money $100-200. I'd look at CUE super cheap, shimano deore 5100 11 speed(upper end of cheap), and Microshift advent X(mid cheap and lightest). I have 5100 and advent x and both are good, 5100 is no the hardtail and X is on the full squish. A narrow wide chainnring can be bought for $10 these days off amazon so that is nothing. PNW makes good external droppers other people take PNW post and rebrand them and can often be found cheaper. Don't take my word for it and my quick google has shown it it and it isn't but tranx external on jenson is $100 and looks like a PNW. I have a brand-x ascend in my hardtail and it is 100% a PNW.