Update: My greenhouse is now complete. It was definitely worth the extra time to level up and secure the base as it feels very solid. Thanks to all for the advice.

Pete - It's a Halls Supreme. My choice was heavily influenced by my wife who liked the curved roof panels. As it had to be situated in a fairly prominent position in our garden I wouldn't have been allowed anything she considered ugly!

Construction was simple enough, though a few of the instructions were a bit vague! Halls - if you're reading this some better quality photos would help. Glazing the back and one side was a challenge because I've had to situate it very close to a shed/fence, but with a bit of forethought it was possible to glaze it from within (good job I've got long arms!). There are a few leaks but I'm sure I can sort them over time with some silicone sealant.

Too bad its autumn, and I've got to wait for the next season to start using it - unless anyone has some good ideas about what to grow over the winter.