Ok, so for option #1 how should I connect things?
I tried connecting the ethernet cable from my modem to the WAN port on the pcWRT. Turning off wireless on the pcWRT, but left the setting DHCP client enabled. I ran an ethernet cable from a LAN port on the pcWRT to an open LAN port on my Linksys 1900AC router. I disabled DHCP on the Linksys, but left wireless on so it broadcast. I didn’t even try to setup the other Linksys rounter as an Access Point, because I couldn’t get internet connectivity with this setup. Any suggestions?