The idea of that funky tool I made is to grab the cam sprocket by the spokes, to keep it from turning whilst the bolt is being wrenched. Ford sells a (no doubt expensive) special tool for the purpose. You need something of the sort, because if you try to wrench the bolt off while holding the camshaft -- like, by sticking a plate in the timing slot -- you risk breaking the shaft.
About the torx bit, I got a set of six for 3/8 drive, of apparently pretty decent quality, for like $20 at Kragen (= Checker/Schuck). With this car, the full set is worth having.