Insulation in a conservatory

[Am happy]

Advice please: -

It has been suggested that in order for me to keep the warmth in and the sun out of the conservatory I should use Aluminum foil and Thermal Wadding with cladding or plastic board. I been trying to do my search but can not find the answers to any of the questions below, before I obtain quotes and be given the sales pitch on what I should get and not what to get, please PM any suggesting or advice. lol.

What I wanted to know is: -

1) - Is there any disadvantages of getting any of these completed.

2) - I would still like a few gaps of natural lighting, would this be possible.

3) - Can I use drape type curtains instead of the plaster board/cladding to cover the foil/thermal wadding?.

4) - Can you suggest any local companies.