When the DIY conservatory is almost fully assembled you may want to think about how you are going to light it. You could go the easy route and put in a couple of table lamps to create a pleasant atmosphere.
The more normal way of lighting your conservatory would be to fit a ceiling light or a combination of light / s and fan. Not only do you get a more even spread of light but you then also have the means to cool it in the summer and by reversing the fan, draw down the warm air trapped at roof level in the winter.
Please be aware that any wiring must be done by a qualified electrician!