Help with WG103 AP setup

First, just a disclaimer: I'm a relative neophyte on network setup. Not completely clueless, but if I knew enough, I probably wouldn't be here asking for help:)

I've volunteered to help set up Internet access at a church. I've purchased 4 WG103 APs for this task. I've got a feed from a switch that I'm starting from. From the switch, I've got a meeting room where I will locate the first access point. I'd like to provide Internet access here as well as relay to the next access point, in an adjacent hallway. There's a spot prepared there for a wall mounted unit to relay the wireless signal to another room down the hallway. No internet access is necessary in the hallway. From there, there's another room in range where the wireless signal will have to transition between floors. There's a conduit leading down to another room downstairs where I need Internet access, and I'll need to run a cable down to the final access point (where the access point will likely need to run off of POE).

So the (desired) setup is like this:

AP1: Wired access from switch to access point. Wireless Internet service needed here, and relay to AP2.
AP2: Wireless relay only between AP1 and AP3.
AP3: Receive wireless signal from AP2, relay to wired AP4 (wireless access at this location desired, but not critical)
AP4: Wired access from AP3 to Internet access to this location.

Any help in setup/hints/feasibility/etc. would be greatly appreciated!