Wireless Extenders

Bought a EA8500 Linksys router. The coverage is good, but I need an extender. So I tried the Linksys RE 6700. It was a pain to set up and didn't extend both networks as advertised, so I returned it. Next I tried a Belkin N600. It was also difficult to set up and when unplugged, would not restart. And it would not extend both wireless networks. Next I tried a Netgear N 600. It was easy to set up, but would not produce an ip address. I made sure the md or mdu filters were turned off as they said.
Then I read an article on MG about using another router as an extender. I did that with my old 10 100 network and it worked well. When the power went out it was easy to restart.
Should I use the same router as I have (ea8500)?

As always, thanes for your suggestions

Al