How talented a mechanic are you, first of all?
A, these are old bikes. Very few shops work on them as standard.
B, Maybe 10% of those few shops will touch a chop.
C, It's GOING to break. Shit will fall off, crack & vibrate loose.
Custom bikes are my true love, but you genuinely have to be able to fix literally anything yourself. Hardtail frames aren't just tough on you, they're hell on electrics, oil lines, engine mounts, seat & tank mounts, gas tanks (unless they're isolated) pretty much everything bolted or welded to the frame or bolted or welded to anything bolted or welded to the frame is at risk.
You also have no idea what the builder did or compromised (there are ALWAYS compromises) that he was willing to live with, when he built it.
Honestly, unless you're 100% confident in your ability to diagnose & rectify any problem, often at the side of the road (at night, in the rain
) I would suggest starting your motorcycling life off with something modern, easy, comfortable & reliable.