Hello everyone. We are having an extension built and want to use aluminium doors (bi-fold type), windows and sky lanterns. I'm getting quotes at the moment but I don't know if one make is better than others. The ones we've looking at so far are Warmcore, Smart Systems (Smart Architectural Aluminium), AluK and Alulux. All the quotes are similar, so we're wondering if anyone knows which is best? Any to avoid? Any other makes we should be looking at? Thank you for any assistance.