For gaming, if you do not want to oc, can consider intel i5 8400. Cost-wise similar to local r5 1600 bundles even after taking into account of z370 pricing.
Otherwise, can go for r5 1600. Would not recommend boards from amazon as i personally think that chances for boards to have issues are significantly higher when compared to cpus.
For atx board, you can take a look at asus b350 prime plus/ msi b350 tomahawk
For matx, asrock ab350 pro 4/ msi b350 mortar
Locally, I feel the MSI B350M Mortar is a better buy. Anyway, buying aboard and buying locally, I feel it is about the same. For new boards and such, local distros or shops can offer a 1:1 exchange if they have stock. They may also help you to troubleshoot, if you bring the whole rig down. Beyond that, I feel there is little benefits for getting it locally especially when the price difference is huge.
Typical scenario when sending an item back to the distro:
1) You will need to take leave because they normally operate during office hours and at most half day on Saturdays,
2) Find your way to the industrial area, which I will normally catch a cab there (both ways in and out of the place),
3) You drop item there and if there is no 1:1 (waiting time for collection typically 4 to 8 weeks)
4) On collection, need to take leave again,
5) Find your way back to the distro to collect (another 2 cab rides in and out of the place)
At the end of the day, it depends on how savvy the buyer is with RMAing things. The above is just my perspective.