Both chips will be vulnerable to whatever Spectre variants AMD is currently vulnerable to. It's less than Intel, but that can always change especially as security researchers start scrutinizing Ryzen more closely.
The 2200G is the better CPU, especially if you want to try to game on the integrated graphics. As for motherboards, B450 chipsets offer more features and allow overclocking on the 2200G. The A320 boards are cheaper but do not allow overclocking. If you want to go with the 200GE and have no intention of getting a better CPU in the foreseeable future, then an A320 board can work.