Using Firewall Portion of Router only With Another Router

I currently have a WNDR4500 for a router and I wanted to keep using it for one reason specifically in the GUI there is an option to have certain wireless devices on your network and guest devices be separated from the rest of the network and I figured with that option in there that is a lot simpler to enable then setting up different networks.

I also was able to trade for a low cost to get a netgear UTM50 firewall/router. Now before I had the wndr4500 router inplace as a router instead of just an AP I had a rvs4000 router but with the security features it offers and the actual power the router was capable of it just didn't cut it in terms of throughput. So I looked for a firewall that provided those features and found it with the netgear one. Others do but they have more of a user max limit on their hardware and netgear does not so that is what attracted me to it.

Now I just want to use the UTM50 as a firewall and not a router so heres my idea for the network setup please correct any shortsightedness.

Modem>WNDR4500(firewall options disabled)>then from a LAN port on the WNDR4500 to a LAN port on the UTM50 I would connect those two that way>Then connect a switch to a LAN port on the UTM50 and have any subsequent switches come off of the one connected one.

How does that sound?

I was also thinking I might need the UTM50 after the modem and then just use it as a firewall into the router so that way everything on the network is covered correct?