Okay the ones in SA are in nat parks so technically you need permission from SA nat parks to enter but dont both as the ones in WA are better and no real restrictions for normal caving (well at leats when I did it)...cave diving Im not sure about?
Getting to them is easy all have roads to them, though 4wd sutable but nothing a subby type car couldnt handle.
Note though some of the caves are huge, so make sure evrybody has at least 2 secondary light sources, rather than the normal extra one. Im done lots of caving in my past (none recently) and was amused when I took my crew into homestead who were less experienced (but not total newbies) to find after a mile in they were lost. We were in one chamber on the way out and I sat down and asked em which way and after 30mins they confirmed they were lost...so dont just charge in thinking all will be okay.
Caving is safe but very easy to fuk up and become unsafe.