Safety Devices cages are a fairly good fit, for what is a universal bolt-in cage, they were used for G40 Cup Cars, so provided you buy the correct model, they come with MSA/FIA certificates, if that’s what you want. The door bars are very low though, which makes access easy, but I question the side impact integrity in a crash compared to a full X in the door.
Regarding window winders- see my build thread for a way around it!
Bolt in still requires plates to be welded and dash board to be cut, you loose a little room around the b-pillar for bucket seats, but most still fit without problem.
Only thing to be aware of with a sunroof model is if you modify the cage (see Robin’s build thread) to clear the sunroof mechanism (i.e. you lower the cage) then head room can suffer. If you’re a short arse like Robin this is fine, if you have a large head like me, then it’s a problem!
Cheers
Pete