Clutch hydraulic cylinders

Advice please guys:
Having problems with gear changes that my mechanic and I have decided is likely due to impending failure of one of both of the clutch cylinders. So I am looking to replace them. Can anyone tell me where I can get hold of master and slave clutch cylinders for a '93 Australian Delivered NA SW20?  Toyota are saying 'have to come from Japan' and $500+ for them, which is not an attractive option. Are there available third party equivalents components in Australia?
There is also CBHaus eBay store but there items are for US delivered cars, which are LHD of course. Does anyone know if these would work - my best guess would be that the slave cylinder would be the same on LHD and RHD cars but that the master cylinder is likely to be different?
Any advice gratefully received.
TIA
Graham

Or you can go to a brake/clutch specialist shop and they can resleeve your cylinders with stainless with new seals.  I have found this to be very cost effective.
 
Cheers

@redtarga  Thanks for the info I'll follow up on that.
 
@artymr2: That's my fallback position the issue is the time off the road - I need to be able to drop off in the morning and pick up arvo as this is my daily drive. So that approach will have to wait until one of my daughters goes on holiday and I can 'borrow' her car for a few days. The current master plan is to find replacement parts either new or 2nd hand and get the current ones refurbished offline so they are available for when the replacements fail!
 
@mandalay:  clutch dude, not brakes! Nice try though, if my brakes start to fail as well I'll get back to you. 
 
After a really good power bleed I haven't had the problem for a week now, touch wood.  It used to refuse to move from 1st to 2nd on occasions. The last time it happened, which was just after the bleed, when I yanked hard on the lever it came out of 1st with such an enormous bang that I fully expected to see half a gearbox lying on the road behind me. I'm wondering now if maybe something internal had misaligned (a pressure plate spring has been suggested) and it dropped back in place. Watch and wait I guess. But I will continue to look for the parts anyway.
 
 

Oops it was late.,
 
Im positive i have that also. Need to check but im 99.9% sure. As i changed everything for new

Here's the promised update:
I took a punt and bought the master cylinder from the CB Haus eBay store as Lithia didn't have a genuine one. Cost me less than a second hand one currently advertised on eBay.... The box it arrived in was stamped (amongst many other numbers) with the Toyota part number 31410-17080 i.e. the LHD master cylinder number. I strongly suspect that the manufacturer is the original supplier to Toyota in the first place.  It bolted straight on and works perfectly. I had also bought a new genuine slave cylinder from Lithia, so now have completely new clutch hydraulics and a nice smooth gear change, all for less than one third the price of the parts alone from Toyota Australia. You gotta love parity with the greenback. 
So for anyone else looking for a new clutch master cylinder it very much looks as though the LHD and RHD versions are identical and/or interchangeable, despite the differing part numbers.
HTH
Graham