Psikerlord#
Explorer
Prince Nuada from Hellboy II was 100% a monk that used a spear and a shortsword. If I were making a character like you describe in the OP, that's how I'd build it, casting aside the monastic trappings and focussing on the class mechanics.
I don't think I would allow reach for a spear. 5e wraps the long spear, lance, and pike together as the pike, so if you want a pointy stick with reach I'd send you in that direction. A regular spear will not be significantly longer than a 2 handed sword, and unlike the sword you will be gripping it nearer to the middle. You don't get reach for a 2H sword (or a maul, or a greataxe) so I can't see that reach should apply to a spear, either.
Prince Nuada is one of my fav characters ever!