I would say, find someone in California with "Potato Bugs" (I'd see them on my porch all the time there, whenever the weather started to get cold & they were still out...they'd move REAAAALLLLYYY SLOOOWWWW in the cold morning air.) They are the closest thing you'll find this side of the "lake" that is very large & "Weta-like". They reminded me of a giant mutant cricket!
Next best thing, if you don't mind something SLIGHTLY smaller, would be a Wheel Bug. In fact, I have some eggs that I hope will be hatching soon. Not sure what I will "charge" for them...would prefer trades, actually, but they are neat buggers. Can't wait to raise one up from a nymph! (And I think I read somewhere that they will last for 2 years, but mine died a few months after laying her eggs. Maybe they need to "brumate" in the winter cold to last that long?)