Just to throw a monkey wrench in what everyone has done forever, why not use a 1" bore supra brake master cylinder rather than one for an fj80?  Is there a mechanical advantage to the fj master over the supra master?  They're both 1" bore and both can be purchased for non-abs applications.

What stemmed this question for me was, 1) I already have a junkyard 1" supra master that has worked fine, and 2) I am replacing the majority of the parts in my system and wanted to assure I'd also have no leaks and went to order my new master cylinder, only to have it pointed out that the lines go in differently.  Now, like most of you, I don't spend a lot of time staring at my brake system, so after going home and looking at it I saw the issue.  On my 1980 hilux, the front line loops up and over and screws in from the top, while on the fj it screws in from the side.

Not a huge issue, but why bend a 36 year old brake line if I can just utilize a master cylinder that shares the proper design?

Sounds like a good solution to me. Give it a try. You may be the first. 

What kind of year supra is it out of?

yeah ill be honest...i didnt use a supra MC, but when doing the turbo setup, i ended up going with Mazda Miata booster and master, which is 7/8ths...
If i need to do an upgrade the 626 has a 1in...
I dont really see the reason not to use the supra MC. If i were you id run with it. Also post some pics and sizes, Are they the same master?