minimum cage size for them your looking at is a 2x2x4ft. You could get away with the size of the one they are selling because you have a female but lights inside cages is bad.. Few reasons here. Chams reach for everything so high burn risk. But the biggest thing is the UVB output of T5 bulbs. You put that inside a cage say it is a 6% strength bulb or a 5.0 you need a full 11-12 inches to the branch below for the levels to be correct for the cham so that it is not overexposed to high UVI levels. So now your 3 ft cage only has 2ft of usable space. They are arboreal so taller cages with useable space is what they need. Now this one comes with a T8 10.0 bulb so lower output then a T5 however you would need to buy a solarmeter 6.5 and see where your highest branch could safely go. Looking for a 3 UVI level. I do not have the exact measurements for a T8 without a screen barrier because most of us do not use them in the US.So a reptibreeze? Those seem to be the only ones of size.
Im a little confused, as both of those enclosures are recommended by reptile shops, they're selling them specifically for Chams.
You live in Wales and these cages are very very common there but it does not make them good for chams. The other thing I really hate about these cages is the venting... There really is not much to create clean airflow. So you end up with stagnant air that they are breathing. Not good for a cham.
Start reading this it will help you alot https://chameleonacademy.com/chameleon-husbandry-program-getting-started-with-chameleons/