The one in Whiterun occasionally sells them too, but it's a rare item for him and he only ever has a couple at a time when they do show up. Things like that led to me adding arrow recipes to the forge.
Btw, what's wrong with the Hunting Bow? The only problem I had with it is that you can't craft them, but I fixed that in the same mod that added the arrow recipes.
All followers come with a hidden hunting bow which prevents them from using any other bow given. Even mages have them, even though I haven't seen any mage follower but Aranea use it. Basically I'm using a http://skyrim.nexusmods.com/downloads/file.php?id=6520 that lets you remove it so they'll equip what's given to them.
Also, I've never seen Eorlund have any Daedric arrows, even on level 65. You must be really lucky, I guess. I don't think I've seen him selling anything Daedric, actually. Usually the Markarth or the Solitude smiths have some Daedric weapons in my game, but nobody else.