Some food for thought...
::: Colorway :::I know I must sound like a broken record, but
Klaxon was a hugely popular group buy. It was the third group buy in that colorway, with Red Alert and Red Alert 2.0 preceding it. I think if you chose that colorway you'd be making a safe bet.
Personally, I think red would be a popular color for the asian communities since it's a popular color used in many of the custom boards. That could go a long way in bolstering the numbers because there are many proxies in the GH community that would provide large orders.
::: Old School Group Buy :::It's more work, but I think if you did this as an old school group buy it could be easier to reach the numbers you're looking for. PMKs system is handy, but given the fact that you have to commit the money up front slows down the process. If you
go back and review the original thread for the Klaxon GB, you'll see what I'm talking about. Pricing was clear, up front and interest was able to build as more-and-more orders came in. There was a lot of peer pressure to put in your order so that we'd tip to the next tier.
Granted, it's more work. You're accepting orders from a Google Form and living in spreadsheets. When you're ready to place the order, you then have to issue PayPal invoices and track down people for payment. After the key caps come in, you're then having to ship out everyone's orders. PITA for sure, but I think it would give time for this to build interest and hopefully yield a successful group buy.