Is the USG110 enough for this setup?

Hi All, I posted the questions below in the Networking subforum, but I also need to know if my product selection is appropriate... I have chosen the ZyWall USG110 for this setup based on my past experience using a number of different ZyWalls (50, 100, 300, etc). My most pressing question is whether the USG110 is enough, or if I should step up to the USG210? The hotspot may have up to 30 people browsing the internet (this is a coffee shop). I would port block most to prevent high usage/torrents/etc, and may limit the bandwidth on this port. See below for details. Thanks very much.... ------- I'm setting up a fairly basic network, but wanted to verify some assumptions I've made and make sure that I'm not making any flagrant mistakes. This is not my primary area of expertise and I know enough to get myself into trouble... I'm setting up a new retail store of ours. The basic setup is a router/firewall (ZyWall USG110) and two unmanaged switches (one 24 port switch and one 16 port PoE switch). The store's computers and equipment will be connected to the 24 port switch (possibly ZyXEL GS 1100-24 or HP ProCurve J9561A). The store's IP-based PoE security cameras (Axis M3004-V) will be connected to the 16 port PoE switch (possibly ZyWall ES1100-16P). These cameras will be recording their data to onboard 64GB microSD cards mostly. Also on the 16 port PoE switch will be a simple desktop. This desktop will be used to display a live streaming view of the cameras and to interact with them/download video if need be. 8 cameras plus 1 computer and one connection to the router will leave 6 ports unused. My assumption was to configure the router/ZyWall such that LAN1 uses subnet 192.168.A.XXX which will be used for the store computers equipment. LAN2 would be configured as 192.168.B.XXX which will be used for the IP cameras and the lone desktop. A third subnet on LAN3 may be DMZ'd and configured for a store wifi hotspot. All of these configurations are done on the router. The switches are unmanaged and the only configuration i would be doing is assigning the switch's IP address to the appropriate subnet. Is configuring the router with these subnets all I need to do to in order to streamline data movement and prevent all the video packets from interacting with the store/equipment data? No data needs to go between the two subnets. The video desktop has a direct keyboard/mouse/monitor connection. It does need to be accessible remotely from the internet. Is using unmanaged switches appropriate? Would you do things differently? Am I better off using a single 24-port PoE (decently more expensive) if I can get all my devices to fit on just the 24 ports as opposed to separating the two switches (which is possible, but leaves me with almost no unused ports)? Anything else? Thanks for the help.