Left Riyadh 2 years ago after 6 1/2 years working for BAe Systems teaching their Air Force studs.
Bear in mind that places like Jeddah, Dhahran (i.e. not Riyadh!) are significantly more relaxed than Riyadh.
The security situation towards the end of my stay was not good, however I understand that it has improved somewhat. Nevertheless my advice would be to go solo if possible.
When in country, our passports were held by the company. Every time we went on leave we had to have our passports endorsed with an "exit/re-entry" visa. This is significant, because it means you can't up and leave at short notice without a lot of hassle.
I'd forget about walking to work. Firstly, your compound will most likely be some distance from the workplace; and secondly, I wouldn't like to be a white boy who walks the same route at the same time every day - get the picture?
Cost of living is slightly more than in Oz.
Shouldn't be a problem getting satellite TV and internet.
Good place to get a petrol-guzzling car if you're a revhead, but watch the local drivers - very carefully!
Keep your head down and your mouth shut.