Yongnuo YN-560II vs Sunpak PZ42X
About $90 on Amazon.com
About $145 on Amazon.com
To make getting a manual power control flash off camera the RF-603s are fine and come with the needed cable so that they can be used to remotely trigger a Canon camera for about $30 on Amazon.com.
Yongnuo RF-603 C3 2.4GHz Wireless Flash Trigger/Wireless Shutter Release Transceiver Kit for Canon 1D/5D/7D/50D/40D/30D/20D/10D Series.
For off camera E-TTL you can use the 60D's built in flash or go to something like the Yongnuo YN-622 RF trigger which sells for about $100 on Amazon.com.
I suggest you watch Syl Arena's free video tutorial and buy a copy of his excellent book, "Speedliter's Handbook". These will teach you an enormous amount about using hot-shoe flash units both on and off the camera.
Canon 7D, Canon EF-S 18-55mm f/3.5-5.6 IS II, Tamron SP AF28-75mm F/2.8 XR Di, Canon EF 70-200mm f/4L IS USM
Nissin Di866, Electra CLASSIC Plus studio strobes & modifiers
Sekonic L-358 Flash Meter, Yongnuo RF-602 Transmitters & Receivers
|AT-6 Harvard by jarud|
from Trainer aircraft
|Monarch butterflies winter roost at Pismo Beach by cjf2|
from Safety in Numbers (Nature)