Access point or repeaters?

Access point is connected to the main router via Ethernet cable, repeater is connected via wireless.

Any of the units should work fine as an access point (except the Micro router N150 as it doesn’t have an ethernet port) and similarly any of them should also work as a wireless repeater. Just don’t forget if you purchase an N300 unit it only has single 2. 4Ghz so as a WiFi repeater you’ll “lose” half your speed due to backhaul and LAN on the same band.