[guineapig]

Unfortunately the only classic item that you could have used to keep your look changed all the time was the old Mask of Deception (or whatever it's called) in lower Guk. The original mask could be used by any class to change their form into a Dark Elf.

But that item was taken out of the game around the time that The Temple of Solusek Ro was released (just like on live) and now the new version of the mask is only usable by bards and rogues.

As far as illusion potions and such, most of those were released in later expansions. They were one shot potions (multishot versions were usually released later), And honestly, you would go through a ton of them if you wanted to perma change your form while leveling up.