I don't have any skin in this game because I don't sell any high end kits and wouldn't participate in a group buy of them, so I can give you an unbiased opinion. Forget a group buy involving more than one style and forget doing a direct buy from an overseas source..
first, you won't get any better price if you buy a half dozen styles than if you buy one....
second, forget any idea of 1000 members participating, that ain't gonna happen and if you have ever tried to deal with keeping track of something for 25 or 50 people you understand that you don't want to mess with more than that....
third, you will have one member needing to keep track of a bunch of other peoples money and with high end kits that could be a big stack of money at that...
fourth, you are going to be moving a lot of money; you pay via paypal 3% charge on every transaction $3.20 for $100 for most it is charged to the receiver of the funds but the buyer has to pay it. That only gets the money as far as the member coordinator, then there is a charge to transfer the funds to the overseas about 4% more depending on how you do it, direct wire transfer might be a little less but would give a foreign source access to the coordinators bank account...
fifth, that money is going to pass through the hands of a person and if they happen to get audited by the IRS they better understand the tax consequences. Uncle Sam can be very unforgiving about things.
sixth, the coordinator better know enough about customs and importing to not run afoul of the "rules" for instance the importer is responsible for labeling them "Made in China" or "Made in Taiwan" not the exporter. They will label them for you at an added cost. That applies whether you import directly from there or indirectly from another country. In fact, it applies even if you just want to resell a few kits that you buy from one of our Australian suppliers. What you use yourself doesn't have to be labeled but what you sell does. It is not overly difficult to get things through customs, if you know how to do it or if you pay the shipping company to do it for you but it's easy to run afoul of the rules.
Given all that, I would suggest that you keep all group buys to dealing with a US importer who already has dealings with the company you want to buy from. Otherwise folks, you are opening a can of worms I don't think most of you will want to deal with. My opinion.