The one thing to note about such small builds is that there is less tolerance for any sort of error or oversight. There's not really much you can do though, you just have to give it a go and fix the problems as best you can when they come up. This does mean though, that if you spend all your money on your planned build, then something doesn't fit, you have nothing to fall back on.
hah theres always the trusty angle grinder, jigsaw, sandpaper, fiberglass and paint. Its not as hard to mod stuff as some people seem to think
bogan...........
Do you have a case in mind? CPU to be oc'd? Or default some itx mobo's limit them volts, Z77 as rock board is sweet if you can find one in Nz.How many HD/SSD do you have?What CPU cooler do you have or would like to use, can conflict with some mobos and case. PSU dimensions vs case layout.