To be realistic, if your GTi is low mileage, forget the chain and stuff like the engine mounting bolts as they should be ok to go again. My £120 parts cost included a new timing chain cover which in hindsight was a luxury. If you are careful when taking it off (its pressed steel, not a cheapo plastic part) it also will go again.
As i mentioned earlier, I'll do a step by step. Its not that hard. but its important to have the right tools.
I always look at these jobs on the basis that when you take it to a garage to have work done, the workshop isn't staffed by NASA, just ordinary blokes. If they can do it, so can you and I!
There's a lot of satisfaction in DIY, not the least in £'s saved...