NOTICE: The upper receiver block in the link is for an AR-10.After building two (and from advice from many on here) the essential stuff for your first build are this:
A good roll pin punch set
lower receiver vise block
a good upper receiver vise block
a good vise
patience
For the lower receiver I've not seen any difference between the cheap mag well style vise block and anything else. For the upper receiver there are several styles that are good, you just want to make sure they use the star lock or the bcg area as their torque point and not the take down pin tabs. This is the one I use:
https://www.amazon.com/NcSTAR-VTHAR...7030768&sprefix=upper+receiver,aps,194&sr=8-1
As for the components of the build, that is like asking which soda to drink for the most part. Best thing to do is make a budget, then research the parts you want and balance the cost vs quality. Just be careful, I set my budget for each build then went over by almost $200 on both lol.