Wiring is fairly simple if you know what your doing (tho I suppose everything is simple if you know what your doing

). It would probably be worth taking to your local garage for them to have a look. An hours labour would prob cost less than buying and postage for a complete loom.
Also, a complete loom may not fix the problem as there may be a component failure.
edit: Also, if the car is not even turning over then there are very few wires involved. There should be one large wire going straight from your battery(+) to the starter, one small wire which is your ignition feed which should become 'live' when your key is in the crank position, and an earth from your engine to your battery (-). Regardless of the rest of the wiring, if these three are OK then your engine will turn over if your starters good)