Hi Shaun - -
You didn't mention if you will be shooting in a high school gym or not. High school gyms (sometimes known as "dimnasiums") offer their own set of problems.
In an effort to save money on electricity, many high school gyms (and football fields too) use "phase lighting", which is some sort of weird combination of tungsten and sulfur light. Your eye won't see the changes, but your camera will when you are shooting multiple frames per second. That means - if you are shooting in one of these gyms, you can have your camera perfectly adjusted for correct color balance - and then have every other shot look terrible.
As one who has shot a
lot of high school basketball, I recommend shooting RAW. Its not really a big pain - in fact, once you get used to it, you will find your post processing is actually lessened. You may need to download the free converter for the 30D, but if you are using version 5.0 or later of Photoshop Elements, it should already be there.
By the way - 300 shots is not that much. Its about what I shoot for a game - and one photo gets published in the paper after all that work.
I'm serious - try RAW. Because none of the settings you apply for JPG images work when you shoot RAW (such as color balance), you do your adjustments in the computer rather than before setting a custom white balance. You just move a slider to get the correct color balance. (Be sure your monitor is calibrated.) Once you get one shot correctly balanced, you just write down the number, and set all the other shots for that. Easy - it really is.
One final point. I used a 30D and 70-200 for awhile before moving on to other equipment. You will often find that at ISO 3200 and at f 2.8, you will still have underexposed shots. RAW will help you recover from that much better than you can do in JPG.
So - shoot in JPG and set a custom white balance if you wish, but I highly recommend you start shooting in RAW.