I've decided to use the Arduino Yun as the central hub of the project, from previous experience of Arduino development they are really easy to get started with, there's loads of information available and the community is great for support. The Yun is cool because as well as a Atmel ATmega32U4 processor it has an Atheros AR9331 processor that supports Linux which means it can be used as a webserver and can even run node.js which could be interesting and it has built in wifi. As well as all that I won one in a previous competition and I want to make use of it! A guide to the Yun can be found here and below is a brief overview of the specs taken from the product page:
"The Arduino Yún is a microcontroller board based on the ATmega32u4 (datasheet) and the Atheros AR9331. The Atheros processor supports a Linux distribution based on OpenWrt named OpenWrt-Yun. The board has built-in Ethernet and WiFi support, a USB-A port, micro-SD card slot, 20 digital input/output pins (of which 7 can be used as PWM outputs and 12 as analog inputs), a 16 MHz crystal oscillator, a micro USB connection, an ICSP header, and a 3 reset buttons."