| Hi tonesanlainie,
You could go to Bunnings and buy a shower screen door for $100!!! Seriously though - you could... or perhaps check out Ebay for some? (i love Ebay... almost as much as I love Bunnings).
Alternatively, you may find it cheaper to have some aluminium sliding windows made to your custom measurements - your local Staff Member at the Aluminium Window Making Place (hehe...) will be able to give you a quote in a few minutes over the phone. From memory there are a few members here that have done it and it has worked out well for them. Personally, i'd feel a lot safer moving a piece of glass that size if it had a nice sturdy frame around it.
Have you started building the enclosure yet? Can we see some pics please?
regards,
Lockie | 
