ESB, just looks more professional. ROTJ kinda looks thrown together to me.
I like the "thrown-together" look of the ROTJ (and Pre-Production) costumes more than the uniform appearance of the ESB version.
To my mind, Boba Fett is a survivor, adaptable to situations and more concerned about the lethality of his weapons than whether or not he looks professional and polished. I mean, he's got all those scratches, chips and that big old dent in his helmet.
Although, to be fair, ESB has way more screen time than any others, and there is something to be said for the continuity of color.
I know you didn't put any of the Pre-Production costumes as choices, but the PP2 has the "jet pack of many colors", one red gauntlet, one dark yellow gauntlet, with that wicked looking flame thrower on it, and the PP2 helmet looks great. It has the dark green cape someone mentioned earlier.
Most of this stuff is subjective, anyway. It's
your money, time, effort and uitimately,
your costume. Pick one you like and go for it!
"You must do what you feel is best, of course".
Keep us posted.