One XBee controlling multiple Xbees using only digital I/O line passing

I am looking at a small project that will use one XBee to control 6-8 individual remote relays with a corresponding XBee. No processing is required and I am hoping to do this with digital I/O line passing and the XBee’s. There will be a control box with 6-8 push button switches used to turn on or off one of the remote relays that is associated with a particular switch. The remotes activate machines that are moved around frequently and are currently controlled by cable connected push buttons.

The remotes can be out of line of sight behind concrete walls or over a steep cliff. Once or twice a week the cables have to been laid out and then reeled back up and stored. Another 2.4GHz control was tried but it lost connection behind these objects. I am now looking at the Series 1 XBee XBP24-AWI-001 modules (802.15.4) from Sparkfun. I believe that these will set up a mesh or point to multipoint network which will allow connections between the control box to remotes via other router XBees that do have good line of sight connection. Is this true?

Using the digital I/O line passing, I am hoping that the coordinator XBee will read the push button switch inputs and broadcast the data to all the other XBee’s. The remote XBee will only have one output pin connected (which matches the switch assignment) to it’s corresponding relay. For example: Switch #1 will connect to coordinator input pin D0 and the remote unit #1 will have the relay circuit connected to output pin D0.

Before I start to buy these XBee modules I just wanted to make sure I am not making a mistake somewhere. Are the Series 1 XBee XBP24-AWI-001 modules the right modules for this project or am I missing something? This is just a hobby project so I don’t want to get too much money into something that has no chance of working.

Any comments are appreciated