I have been looking at all the variations of lowers and uppers and just everything to put an AR together. I have absolutely no clue where to start. I saw on a deals thread that spikes stripped tactical lowers are on sale and didn't know if I should grab one or 2 while they are. I guess my real question would be is do any uppers fit into lowers and do any lower part kits fit into any stripped lowers? Should I just buy the stripped lowers now and then find a lower part kit that I like and put that into it or should I just buy the stripped lower and parts kit at the same time? Also, if anyone can point me in a good direction on where to get started with all of this I would be thankful. I didn't see a sticky or else I would have referred to that.