Hi harryharris,
This is a really good question. One of the reasons that Im setting up my present workshop is to be able to make windows, french doors, doors etc. Its impossible to find the right profiles, quality etc in Sweden. At least for a reasonable price. So instead of buying this for some 20'000 £ I spend it on tools and machines.
But still its no childs play doing these things. It would be very nice to get examples of solutions, techniques etc.
I will post any progress worth mentioning on the subject and hope that other will do the same!
take care and good luck,
Daniel