Well you have to decide on the caliber you want then see if it makes any sense buying it in an AR upper. This could be a case where a complete 30-30 lever action rifle makes more sense. Or a value priced bolt action in .308 or 30-06. These rounds are very common and easy to find.
The biggest issue with assembling an AR isn't so much getting the parts together right - it's getting the right parts together.
US Army 1966-69, VFW Life Member, Retired Geek