I am SO VERY close to X2-X's, just need to get my armory up one more level and research it. Though I would prefer a level 12 armory, and I need to get my crystal and gas mines a little higher up too, so it might be a little while. If you're willing to wait, i can tell you when I'm ready.
The best way to do it would be to send the resources as I build the transports, so then I have the resources to build the next ones. With 15 transports, you'll just be able to send the amount of resources for 1 x-2x. I would just send the amount for 1 x-2x, and if you want to you can make more transports, but I should be able to cover the costs until you pay me back.