I would avoid it personally - cheapo aluminium frame just isn't worth the time and investment
Be prepared to spend way too much money
not necessarily on the original bike, but getting something to look the way you want will take more dough than you think. All these Youtube bike guys (Monkeyshred, Alan's Bikes, Old Shovel, etc) have big parts bins and know how to find stuff efficiently (and they get given things)
IMO you want to have a decent frame to start with - doesn't have to be especially posh or expensive, but needs to have something going for it, and you need to consider what kind of look you are after. I think often late 80s or earlier 90s MTB's make better candidates for this sort of thing - less racey geo and more adaptable
if you're in the uk something like an old Muddyfox, Saracen, Orange, Ridgeback, GT, Specialized, Marin, Kona, etc - or even a Raleigh if you know what models to look for (someone was selling a nice one the other day on here) - or the obvious old rock hopper/hardrock route though thats' kinda been done to death already
don't expect to get back what you put in if you decide to sell it