DIY lean-to greenhouse - ideas sought

Later this year, or early next, I need to replace the existing lean-to greenhouses before they completely collapse. They are south-facing and back onto a brick wall, the other side of which is an old apple and log store. The plan is to have a dwarf wall at the front, maybe 2 blocks high, and then to glaze everything else. The size will be about 6.5m x 2.5m, with a door at one (or both?) ends and some openable sections in the roof. There are some mature tree canopies above the area so I wonder whether the roof glazing should be polycarbonate or wired glass. I presume others here have done something similar so I'd appreciate suggestions for suppliers of "bits", and for design details to consider.