If you are going to go to micro center already, it would be worth trying to take advantage of their CPU/motherboard combo deals that they run. They tend to give you around $30 off the combo. You will want to pick up a Z370 board if you are going to go with an 8700k. There are plenty of mid range boards around the $150 mark that would work for you. You also need to pay attention to the form factor in relation to your computer case ATX is the most common, but smaller computer cases may only support mATX or ITX motherboards. As for cooling there are many good options. Air cooling is simple and high end air coolers will produce similar results to your mainstream all in one (AIO) liquid coolers. Something like a Noctua NH D15s or a Cryorig R1 Universal will give you plenty of headroom for overclocking though they are quite heavy, so I would not recommend them if your system is going to move around a lot. If you plan to just run stock you can get away with a smaller air cooler. AIOs like the Corsair H100i V2, H115i, or NZXT Kraken series will also give plenty of headroom for overclocking, and can be a bit more aesthetically pleasing, but, as with anything, more complexity means more that can go wrong. For the most part AIOs are pretty reliable these days, but sometimes it is just nice to have the straightforward simplicity of an air cooler.