Best pc parts for minecraft?

The most important part of a minecraft pc is the CPU!
most games need a good GPU, but minecraft relies heavily on the CPU, i would recommend an intel i5 skylake processor or more, and a decent graphics card.

Well, Minecraft is a VERY easy game to run. Any computer for $1000 is going to have no issue playing Minecraft. However, as for lag, that is an issue concerning your internet connection and the server's strength. A weak server will always lag no matter how fast your internet, and no matter how great a server is it will lag if your internet is slow. Try going to some other servers and see if the servers are the issue or if it's your internet. If your internet is the issue, well than maybe ask your parents (or if you're an adult, think about it yourself) and see if they can get better service (not likely I hate to say).

AMD FX 8350
R9 280X
8GB OF RAM
1TB HD 7200RPM
1080P MONITOR

That's a good PC to run Minecraft 100+ FPS on max settings.