It's the Type C 2 pronged round plug same as russia http://en.wikipedia.org/wiki/AC_power_plugs_and_sockets
ATMs are no problem in Kyrgyzstan, many machine dispense either Kyrgyz Som or US Dollars. However, to the best of my knowledge, the ATMs in Turkmenistan do NOT accept foreign cards. While there are rumour of some ATMs working in Tashkent, they are almost always broken. Some exchange places allow cash withdrawal on major credit cards.
You do realize that the Turkmen transit visa takes up to 10 days to process. While they don't keep your passport, you'll need to backtrack to Tashkent/Bishkek to pick it up. Where are you going first? And what's your nationality? Do you have any visas yet? Where are you flying in and out of? When asking about visas, nationality is very important.