There is plenty of information regarding slave cinders for the t5.
Search the v8miata forums or monstermiatas. They usually use stock Miata slave cylinders adapted to the t5 with some brackets. I think the maker of the v8miata kit provides the brackets. Anyway, there are plenty of mustang guys with custom slave cylinders are well. Mostly push style. The pull style doesn't like the heat from sitting under the headers, and they just don't last as long. Going for a push style that is original to any car would also make the part easily attainable, since it's only a trip to the parts store away. Rather than ordering and waiting for it.
http://www.v8miata.net/ford-v8-miata-build-threads-52/1991-miata-monster-5-0-build-sn95-1908/page3/Post 71 has some pictures of a Miata slave adapted to the t5
Some more I found from some mustang guys.
http://midnightdsigns.com/Mustang/HYD%20Clutch.htmhttp://chris66dad.tripod.com/id32.htmlI have my rx7 and a 5.0/t5 waiting to go into it. I've done a little homework. If you went with a bracket kit provided, I would still try and find an OEM piece that fits, just so I can locate them at a local parts store. I personally think push style is more reliable, but this method also keeps the the hydraulics farther from the heat of the engine, and headers, as long as the exhaust isn't on top of them.
These articles should provide some ideas for what you want to do. Just remember, if you go with a push style, behind the bell housing, make sure you have enough space for the slave and exhaust. And don't let the hydraulic lines sit on those hot ass pipes.
When I get ready to start really getting into my swap, I'm probably going down this route. I can't give you any information on how well it actually works, just passing on information to help you brainstorm ideas.