I've seen that capacity fermenters from ibrew (www.ibrew.com.au i think) but not boilers.
I would think its prob a good idea to search for 2nd hand from a business with a big kitchen (military, big nursing homes/villages, other hospitality places like hotels)
If you know anyone in the hospitality industry ask them what brand all the cooking equipment is in the kitchen and you could approch the manufacturer/distributor directly and they prob have a large range of large goodies!
ok - in sydney u have this mob.. http://www.wpreedy.com.au/WP_Reedy_home.htm
they have a Stockpots With Lid
Professional Cookware, Heavy Gauge Aluminium with 4mm wall & base thickness - 140ltr code STOCPHDW/C140 - diameter 580mm depth 519mm
They wholsale to the catering industry - have SS paddles - for 35.00 600mm as well.
their rep delivers to Canberra as well - very good prices.
u should check out their catalogue and stuff - they have almost everything - including cheap digital thermometers.