Forget about any boxes from Sim Lim.
RAM is important 2GB is recommended.
Chipset best is Amlogic S905 series. S912 is also good. Rockchip RK3328 is also okay.
5Ghz wifi is good but you can use Ethernet as well.
Best for new users is Mi Box S global version, you have to buy from on line at about S$70-86. It has good 5GHz wifi, S905X or S905L chipset, 2GB memory, 8GB storage, Google certified Android TV OS, Netflix 4k and YouTube 4K support, Chromecast 4k function built-in. Nothing beats it in terms of value and brand name in the sub S$100 range.
For apps you have to Google, there are many. I can only recommend one which is legally approved by Chinese Government. Huawen TV for overseas Chinese. You can try it on your Android phone first.
http://www.5itv.tv/