Does anyone know any good lifebar tools that I can use? I'm making my own lifebar but I need to design it in a .sff file.
There are none you really need for that specifically. If you can make characters, you can make lifebars. Just design them in photo editing program first. Then save them out as indexed .pcx files and you're good to go from there.
You just save it has one using your photo editing program. Save As ... type .pcx. Make sure you index colors prior to saving. There are plenty of tutorials on the forum on how to do this, so I would look at some of them if you don't know how indexing works. Gimp is free, so I'd try that out if don't have something that can save to .pcx.