Any regular Tamiya TRF Damper or TRF big bore damper (not SSBB) should be the standard size. High quality, tons of replacement parts, and should also match the AE colour scheme. They also come with short and longer eyelets.
One more thing, the original TC7 (not 7.1 7.2) shocks should be standard size, so why do you need them longer? Do you need more than 6mm ride height?