I use a laptop and have recently discovered Itunes - great stuff, radio programmes Podcasts, music....
It's not a deal breaker on this issue, but because you are currently using iTunes if you want to stick with it, then you'll have to go down the iPod route.
Most MP3 players are moving more to the complete media devices, so all will have some features you won't use if you've no interest in films etc (however, I don't use video function normally but do for flights and travel where it is a very handy thing to have).
You won't be able to sync the music or podcasts as easily with your itunes subscriptions if you don't get an iPod.
Having said that, it isn't impossible some like the Sansa models allow you to drag and drop, so you can do this from your iTunes folder on the hard drive (as long as the digital rights allow you to). But also most podcasts are either through networks or if not they have a website and you can download direct from there, so you won't miss them. The benefit of iTunes though is you can subscribe and it updates automatically.
So if you want to keep using iTunes and want something simple to just plug in and sync with your media there, you'll need to go for an apple product.
If you want to look at either a different media system or even don't mind individually downloading things from websites etc, then there's a whole range of decent MP3 players you could use.