I love that color man, nice job
Brakes? Depends on yer price range - but yea, although the individual components of a front disk brake aren't pricey at all - it adds up quick as you'll need a fork (mounts) and wheel (hub) as well as the caliper and rotor. Upside is it's an opportunity to get front shocks while yer at it.
When I was lookin' around I found the least expensive way was to buy a cheapo bike w/disk and strip it, used or new - this was often a LOT cheaper than getting the components separately. Catch is - cheap disk brakes are... well... cheap lol, the inner brake pad drags on a lot of them and there's no way to adjust it.
Second was to go to yer local bike shop and see what they've got for take-offs. Used or new - a lot of people "upgrade" their front shock and/or disk brake, the stuff they leave behind is often of high quality - but quite inexpensive (depends on the shop ofc).
I ended up goin' with a Sturmey Archer drum brake, they're about $50 (mine cost more 'cause it's got a genny in it FTW), but you'll still need the rim relaced which adds about forty bucks or so to the price *shrug*
The least costly method is ofc just adding rim brakes. They work well provided the pads are high quality... and it's not raining lol