With the d5000 you are limiting the setup to the 35mm, and anything long is very expensive. I like the K-x option with the 200mm lens with the external flash. Then the XSi 2 lens kit with the external flash. It just gives the op more options. At times the flash may not be appropriate to use, the higher ISO may allow for a decent shot.
Both the pentax and canon options will keep him within budget with the flash, so it will work out the box. And gives him time to think about a fast prime.