i can suggest gl.inet AR750S-Ext (slate), tiny travel router but full compatibility with openwrt, decent specs to deal with most of task, but only 3 eth ports (1wan+2lan).
maybe could be better idea for 5 to 10 devices to look into any linksys router, the only problem u face with linksys's routers is they dont have full compatibility with wifi drivers (linksys havent release the opensource), so depending on the model some features are missing. Still for any other task, this routers are pretty decent on specs to deal with anything you need.
The Slate is a great travel router (I own two) but not for 600+ Mbps. For those speeds you generally need ipq40xx or faster. The Linksys EA6350(v3) is a good “budget” choice at ~US$75. The ipq806x units are more powerful, as are the mvebu units.
To get gigabit rates and run SQM you’re looking at x86_64 and a separate AP and managed switch.