Not sure why this is in Mac Mods but I will answer what I can anyway.
3) what warantees should i look for? how long? are they work the money?
The official apple warranty is one year (even if you buy it Education), to my knowledge there are no other warranties available in Australia.
4) what accessories should i be looking for?
The 10GB (Second Gen) and the 20GB model both came with a wired remote and a (pretty crappy) carry case.
The current (Third Gen) 15GB and 30GB iPods come with a wired remote (the remote uses a different connector and is not interchangeable with the 2nd gen one) carry case and a dock.
5) what costs more, the iPod designed for Mac or Windows?
They both used to cost the same amount, but in the current iPod lineup there is just one model for both platforms.
6) should i be better off paying extra for the new generation?
You get a smaller form factor, an on the go playlist, some more games and an alarm clock. It all comes down to how much that is worth to you.
7) what is the RRP (recommended retail price) for this iPod?
Since the 5GB is no longer available, there is no RRP. But you can check out all the new pricing at
http://www.apple.com.au/store/
You may also like to check out the firesale page at
http://www.nextbyte.com.au/ for older iPods (with warranty)
Cheers,
Mark
Next Byte - Glenelg, Adelaide