I'd definitely get a flash player for running.
The question is if you need the hard drive player.
Some might decide on a large capacity flash player, and only that.
Depends on your usage. I never use my ageing hard drive player... But if I'd been stuck on a train for half an hour every day, I probably would have. As it is, my 2 gig flash player is enough. The old 256 MB player was getting too small, which is why I got the 2 gig player. I stuck too many must have big files on the old player, and got tired of listening to the same music all the time.
to get a normal hard drive player and then a designated "running" player?