Modernica sells barstool bases for the Eames shell. You can go to their site and mix and match the various colors of shells with different bases, to see what they'll look like.

I personally find the shell chair really comfortable, and I think they'd be great as bar seats because you can actually lean back in them.

without a sense of what sort of a look you're going for, this is just a shot in the dark, but how about drafting table stools?

If the stools really will be between the kitchen and another room, consider stools that swivel. That way, by sitting sideways, your guests can be part of the action in both rooms. Also, it's fun to swivel back and forth on a stool.

I have counter stools by Pier one. Sorry but all i remember is that the name begins with an A and they are on clearance.
Hope it helps.

I have a set of Calligaris stools that are fantastic.
http://www.dinettica.com/productdetail.asp?modid=376
They're super comfortable.

Have you considered butting a table up to the wall?

Or perhaps a cantilevered "bar" at which you could sit at with chairs.

I'm afraid that it may be slightly uncomfortable to sit at that wall the way it is because the overhang is very small.

For our kitchen peninsula, we went with the "Spin" from Crate&Barrel. It's fairly simple (design-wise), swivels and is available in two heights.

Before we bought our dining room table and chairs, we ate all of our meals there -- and it was definitely comfortable enough for us (although I think C&B used to sell a cushion for it).

A few years ago I scored a couple of Parsons-style barstools and four matching Parsons dining chairs. They are very comfortable, timeless, and best of all come with changeable slipcovers for washing or when you want to change the look of the room.

http://www.greenteadesign.com/reproductions/black-lacquer-bar-stools.html

I love these stools. Versatile and v comfortable

rlm, those are just like my Pier One counter stools. Except mine are wooden.

I looked a LOT for just this combination of beauty and comfort, and ended up going for the Cherner counter stools.
http://www.chernerchair.com/stool-wood.htm

I love them and they are super comfy, not to mention a design classic...

I love the clean, architectural lines of the Franklin stools from IKEA: http://www.ikea.com/us/en/catalog/products/20059301

But unlike the Eames stools, these are NOT great for leaning backwards in. :)

DWR has a good selection of stools. The LEM Piston Stool may be expensive, but very clean and comfy.http://www.dwr.com/productdetail.cfm?id=4746

I'm a big fan of the Emeco aluminum Navy Stools. They're super sturdy and have a back so you can really sit in them. They don't swivel, but they're very light and easy to move if your guests want to face the living room.

http://www.dwr.com/productdetail.cfm?id=0074

Measure the height of your counter and get a stool that is the right height - there are "counter" and "bar" heights.

I have these and, because they are leather, they're comfortable, very light and visually very minimal http://www.dwr.com/productdetail.cfm?id=4726

i'm selling these!!!! They are in great condition too! Email me :)

The Scoop Stool by Turnstone, a Steelcase company, is relatively reasonable and I think damn cool.

http://store.steelcase.com/ProductDetails.asp?ProductCode=TS30701X

Lots of luck!