|Ok, the details help us to help you.|
You can achieve separation. On one router (router 1), don't enable wireless. On the other one (router 2) do so and configure it. Plug wired clients in to router 1. Wireless clients will connect to router 2.
With this type of scenario, there's no need to connect the two routers since they'll be accessing the internet separately as compared to sharing a single internet connection.
That is of course, unless you want them all to share one LAN. This makes it more complex, but it's still doable. If that's what you want to do, click on my name above in my reply and read my "adding a second router" how-to guide. You'll want to use the LAN port to LAN port scenario.
LAN IP: 192.168.0.1
DHCP Scope: 192.168.0.100 to 192.168.0.199
DHCP Default Gateway IP: 192.168.0.1
LAN IP: 192.168.0.2
DHCP Scope (for wireless clients): 192.168.0.200 to 192.168.0.225
DHCP Default Gateway: 192.168.0.2
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.