Size Designator

Picture

This item allows you to set your size using a system like the worldedit wand.

You right click on your first position, then on your second position, and then right click on the size manipulator.
This will tell the manipulator what blocks you want to take with you.
You can sneak and hold right click to see the area that you've selected.

Keep in mind you still need size upgrades, each size upgrade is equal to 256 blocks so with max size upgrades you can take a 16x16x16 area aka 4096 blocks.

Info

A new method of teleportation is being worked on that will be much faster, so you can do larger amounts of blocks at once.