I'll second the Shimano Stradic 1000Ci4 if you don't mind spending the money on it. I have used mine more than any of my other reels over the past year, and I just can't seem to put it down. We got my dad one from Gander Mountain's website back right before Father's Day on sale with an additional coupon. It ended up being about $140 shipped.

I have used a Sedona 500 on a 5' ultralight, and it feels about right for a rod that size. However, for a rod bigger than that I would go with a 1000 size reel. 750 would be great, but I don't know of any Shimano reels that are still available in a 750.

If you can find one, the discontinued Stradic 1000FI is still an excellent choice. I know lots of places were selling them for about $100 or even less in the past few months, but most of them may be sold out by now. The new Stradic 1000FJ is a very nice reel (although mine came with a bad bearing), but at full price they are only $20 less than the Ci4 version.

I think you would be happy with pretty much any Shimano you pick. If you plan to just pay retail, I'd highly recommend buying it at a local store and feeling all of the ones they have in stock in the model you plan to buy. There can be a pretty big variation in smoothness between different reels of the same size and model. If you do buy your reel online, you can switch it out at a local Bass Pro or other big retail chain store without a receipt if it doesn't feel very good. I had to do this with the Stradic Ci4 we bought for my dad.