Hi Huge E
I just complete a conservatory to sunroom conversation for a friend of mine. I put insulated silver foil under the glass on the inside. Really good job as you then don't see the framing etc for the TGV from outside. Also looks well. Have to say it was a slower job then i though taking 9 full days on my own. Slow job hiding all the nails with a lot of angle cuts. Even with all the right tools and a big van to get the material.
On the price it cost about 900 euro in material (framing insulation and quality TG) I also made my own beading.
I actually have some pictures of it on my website
Hope that helps.