You can't really do your timing chains "at the same time", you might want to do them though when you are changing your clutch.
Timing chains will last for a really long time (at least 200k) if you use good oil and change it frequently. My MK3 has about 90k miles on it, with synthetic oil changed every 3k miles my engine is as clean as it possibly be, with 100% perfect timing chains and tensioners.

How'd you like Eurotech by the way? I've heard a lot of people bash them, but thats because the owner doesn't hold his word sometimes, and he disappointed a lot of people after the Southern Volks show; technicians there are really good though. When my car was owned by the previous owner, the majority of the work done to it was by Eurotech, and everything was done perfectly (now I work it).