World of CNC (aka Marchant Dice) are overpriced for what you get, and that’s putting it in a way that won’t get this site threatened with legal action.
Routers aren’t really my thing (machines built out of big lumps of cast iron made to much metal are!), but routers built from wood are usually pretty poor. They’re usually dimensionally unstable, resonate, and generally not that strong. If you do put the time/effort into building a wooden structure that is strong and stable (aka fully sealed torsion box construction), you would normally be cheaper/quicker making it from metal, and the metal one would still be more stable/stronger (unless you use some really stupid design!).
A well built CNC router will even handle aluminium with minimal effort.
If you are serious about building a CNC router, head over to mycncuk.com and have a read through some of the build threads.