Hemingway Jones and I a few years ago discovered the Waterman Phileas fountain pen.
It writes beautifully, has a choice of fine or medium point, a lovely gold and silver color nib, and comes in a variety of colors. We got the fine point, and are quite happy with it. Don't think I would want anything thicker. To top it all off, they are very reasonably priced. The most expensive I've seen it is $50. They usually can be found for between $32-$39. For Wateman quality, and it is quality, that is a superb price. I have the roller ball too, it's quite nice, but I like so much about the fountain pen. It has a sort of romance to it, it is elegant.
We both bought ours at Staples, but I just checked out their web site and they only had the roller ball version. So, I would suggest doing a search under "Waterman Phileas". Could not find it on Amazon anymore either. But did find a few pen shops offering it.
Here's the link to Waterman's description of it, and a picture. They do make it in a variety of colors; marbled green, red, blue and a classic flat black as well. This is how they describe them "Waterman Phileas Collection: PHILEAS takes its inspiration directly from the Art Deco period, with its oblong shape, cigar band ring, its 23 carat gold electroplated, engraved nib and stylish clip. A journey in time through the world's most beautiful colors. Phileas is available in fountain pen, rollerball, ballpen and select 0.5 pencil. All Waterman pens have a worldwide lifetime warranty."
Here's a link to a few nice pen shoppes that have them in stock