Welcome to the forum @mgp43! Your build configuration looks very solid. If you wanted to save some money, you could definitely go with a B450 motherboard, but I would strongly advise against it, given AMD has recently announced the next generation Ryzen processors will only be compatible with X570 and B550. Since B550 is not available, X570 would be a wiser investment in the long run. 

One thing to keep in mind if you are in to the RGB aesthetic is that your motherboard and graphics card will require two different RGB control software since they are from different manufacturers. If you wanted to control your GPU and motherboard in-sync, you'll need this particular card: https://www.microcenter.com/product/617450/gigabyte-geforce-rtx-2060-super-gaming-overclocked-triple-fan-8gb-gddr6-pcie-30-graphics-card.

What kind of monitor do you have? I know you mentioned not needing accessories, but it's definitely worth pairing your RTX 2060 with a decent gaming monitor. Since Nvidia now allows G-Sync compatible mode on Freesync monitors, you can save some money by using a high refresh rate Freesync panel, or if you do have a G-Sync monitor, you'll definitely enjoy the benefits of Variable Refresh Rate technology. I've upgraded from a GTX 1070 all the way to an RTX 2080 Ti, but nothing compared to my upgrade from a 120hz non-VRR panel to a 120hz VRR panel. The smoothness it adds during gameplay is just phenomenal, and I cannot recommend it enough.