I just go with the standard "the best figure available" line and go from there. Example, VOTC Han, Leia, Tusken Raider, and Stormtrooper, Saga2 3PO and Tarkin. EB Chewie. (VOTC has that ROTJ hairdo, after all, and I'm going for an "original" Chewie.) "Resurrgence of the Jedi BP" Luke, R2, and Old Ben. Legacy Vader. As far as the Jawas, I would personally go with the Commtech Jawa, just edging out the 30AC version.
Heck, on my 100 list there are still a few figures that haven't been made yet (I still really really want an ESB Chewie that has a sculpted on threepio pack as opposed to all the variatons of loose 3PO parts they've given us.)