Do you ever use Imperial Shipyards? http://www.imperialshipyards.net/SMF/index.php#c1
I think you may have already told me about it. But I found it last night and joined and was browsing the custom diorama's and 1/18th figures and vehicles and I'm really impressed by what's there.
They have a 6" section too. And I think a trading section. Like if you still can't get a hold of a Sabine, and can't find one online form a store, there may be a dude or chick on there who's got one or knows a place to get one.
I'm going to upload pics of my customs there and try to get some advice from senior members for my projects.
Just thought I'd mention it to you in case you didn't already know. :{