Difficulty of Wiring gauges in Options

[BigEdge169]

Recently I came up with the idea to make a custom gauge cluster to replace my stock unit. I could fit two 3 3/8 inch gauges (tach and speedo) and two 2 1/16 inch (water temp and fuel level) into the stock cluster location. I'd also like to put 3 other gauges in the pocket beneath the radio (probably oil pressure, oil temp, and A/F Ration, but possible a voltmeter instead). 2 1/16 inch gauges will fit if you cut into the dash trim slightly, but it would look really nice.

Anyways, to anyone that has wired in gauges before, how hard is it to do. Also, I'd only like to do this if it is possible to make LEDs for all the warning lights (and work them into the cluster) so that I can still know if something major is going wrong, so is this feasible too.

Also, I made up a cardboard mock up of what the cluster would look like, let me know if anyone wants to see it so you can know what I'm looking at doing.