If you want to be able to see the photos, the Epson P-2000 is definately the best bet. The Vosonic VP6210 might also be useful for you, but the screen isn't as big.
If you just want to store the photos (rather than see them), either the Vosonic VP3320 (in either 60/80/100GB sizes), or the Compact Drive PD70X are great options as they are considerably less expensive than the "screen models". The PD70X runs off AA's which is nice, but the VP3320 plays mp3s. Both are around the same price and have very fast transfer rates and good battery life.
The ipod is s**t for photos because it only allows transfer at USB1.1 speeds meaning a 1GB card takes ages (1/2 hour) to transfer and nearly empties the battery. See this thread for why I'm not so hot on it. The above devices transfer a 1GB card in under 5 mins and do multiple transfers on a charge.
Finally, I assume you mean Nikon Coolwalker rather than Coolscan. The Coolwalker is nice, but the screen isn't as good as the Epson and I think it is a bit overpriced for it's capabilities. I've heard good things about the Apacer CD burner units, but never used one myself.
Look forward to hearing what you choose and why, so we can all learn about options.