Question about AMD Ryzen 5 1500X

Looks good in general. 120GB could quickly become a problem if you want to have several current games installed. The 30.- more for a 240GB SSD might pay off (Kingston SSD A400 240GB, 2.5", TLC (240GB, 2.5").). But the Tomahawk also leaves you the option of upgrading directly to an M.2 SSD later if you realise you need more space.
For everything else, it depends on how much you can/want to spend. A fully modular PSU or a "better" case might still be worthwhile. I personally used the Sharkoon T4 for a PC, and after a few months it had a loose contact with the on/off button.