What is a Pro Micro?
I don't see that as a variant.
I have PCBs on order, ATMega1284 Mini, that will be small like a ProMini but has the 32 IO pins of a 1284, dual hardware serial ports, 128K RAM, and the biggest SRAM of all the variants, 16K. Already left China, just waiting on arrival. I ordered 50, will have plenty to offer around.
Details/discussion in this thread
http://arduino.cc/forum/index.php/topic,112020.0.html