Happy New Year, and welcome!
Please spend some time reading the wiki and forums, there is a lot of information there. Look at the user setups for example.
It's difficult to recommend hardware for the core, as there are so many motherboards and things out there. Most things will work. One thing I will say is don't spend loads of £££ on the best kit in the world, LMCE requires only modest hardware.
Same story for MDs; almost anything will work, so you need to think what your requirements are. Does it need to be quiet? Low power? Small/flat? Cheap? SD or HD? Etc etc. The ability for it to PXE boot is of course vital!
Do you have any experience with Linux? Even if the answer is yes, I would recommend only buying a few bits and pieces to get yourself started, and experiment with it. Don't buy everything at once.