Sunseeker, my husband was an architect. He drew the plans to turn our second bedroom into an ensuite for us and added a conservatory for a second bedroom for friends and family to stay. We had it priced, and had a builder lined up for the next year. Then my husband was diagnosed with brain cancer, and died less than four months later, so we never had it built.
The drawings, which I cannot bring myself to get rid of, are on his computer. He died in January 2012.
So I know where you are coming from. Unfortunately, I cannot advise anyone else on conservatories, as it was individual, designed just for us, and the builder understood as he was here when Ken was diagnosed with brain cancer. He was repairing a roof for us, so we used to give him the keys to lock up whenever an ambulance turned up for Ken.
That's the sort of builder you need, someone who cares.