I need some help with a little wiring project I want to do on my 1993 Sapphire Cosworth.

I have decided to replace the engine wiring loom but want to build my own loom rather than buy one off the shelf. Before I get started I have a couple of questions which I hope someone can help me with.

Can anyone tell me what gauge of wire is used in the originally Cosworth engine loom or what ampage wire I should be using? Is there any tools available to measure the wire gauge in my current loom?

Also can anyone tell me where you can buy the small yellow labels which go on the loom to identify what each plug is for? I have seen these on some aftermarket looms but can't find them on the web.

Thanks