Why not join the club and also come along to some meetings and outings? You will find the members have done most things that can be done to a Mustang and also a lot of things that would normally not be done. Between them, you will get some really good advice.
Bunnings Hardware often have angle grinders and blue plastic sheets on sale which will get you on the way with your project. ;} Personally, I would restore the hardtop and get some good experience and knowledge. Then, go find a convertible and restore that. :_ You will get better returns for sure, I think.
:] [/size][/color][/b]