If you're going to get a flash for your 60D you should also start with a Stofen diffuser - a white plastic diffuser that fits over your flash head, you will lose perhaps about 1 x Stop of light but it will really help both spread & soften the light, either in bounce mode (off the ceiling or walls) or when pointed directly at your subject. Plus they're quite cheap too.
Regarding battery cells, I use the Sanyo Eneloops 1.2V 2,000 mAh and they are the best at retaining their voltage which means you can use them right up until they run out without losing too much performance. The most important part of ensuring that you get the most out of them is to use an Intelligent Charger unit, particularly with respect to the speed (current) of charging - a quick rule of thumb is to use C/5 where 'C' is the battery capacity, so 2,000 mAh ought to be charged at a rate of 400 to 500 mA. You can buy faster & more powerful 'quick' chargers but then you definitely will not get 1,500 cycles from Eneloops.
When I recharge my Eneloops (and I have 36 x AA cells), I normally get more than the stated capacity, at around 2,240 to 2,250 mAh and they always display either 1.48V or 1.47V when fully charged. The trick then is to recharge when the voltage drops below 1.18V. Finally, unlike most other brands, Sanyo Eneloops are classified as LSD battery cells, that is Low Self-Discharge, so they're perfect for keeping in expensive electronic items such as flashguns or camera grips for extended periods of time (shouldn't leak and will work even after a prolonged period of inactivity).
Also if you're new to flash photography, I'd recommend getting a cheap 3rd party clone for 150 bucks for now, especially as the 430EX II is likely to join the Canon discontinued line very soon, so you can learn with a cheaper speedlite on-camera now, that you can use later as a 'Slave' off-camera as your flash photography improves.