damnable

Hello,
Thought it would be a good time to ask.
Basically I am after a pair of bike shorts with the wonderful padding. As I find myself going out on gradually longer rides I find I am getting less comfortable with my unpadded shorts.

Ok what I want (need) is a pair of what might be called mountain biking shorts with the skin tight padding insert sitting inside a pair of more baggy style shorts. I don't feel comfortable wearing just the skin tight ones and don't think I ever would (even if I had the perfect body). I have only seen this style in the mens sizes, but a lot say they are unisex so I am hoping it won't be a problem getting a pair of these (yes I am a woman in case you didn't realise). It looks like I would be about an XL or XXL from the charts but I have yet to try on a pair because I can't find this style at my LBS let alone in that sort of size.

So, what I would like to know...
How much should I expect to pay for a pair?
Where might I buy some? Keep in mind I am in Australia. Also, I don't mind buying online (in fact I would probably prefer it because I don't have to chase around as much) but I would worry about getting the sizing correct.
Would buying mens ones or ones listed as unisex be good?
Any other recommendations?

I realise these have probably been asked before, but I am hoping for possibly more contextual information in terms of larger sizes.

Thanks for you help