Hi All
Hey, I would say, if budget is not a concern, go for a nice OMAS, in celluloid. Just have in mind that OMAS nibs write a little broader that most of pens, e.g. a fine OMAS will write more like a medium modern Duofold, but with a good amount of flex in the nib, specially for the F and M size.
If you can find it, get an old style Paragon or a new style Milord, both are great writers with classic design, and can be found with beautiful celluloid patterns all along the pen (without the metal section of the new Paragon)
I think novelli.it can find some nice celluloid OMAS, specially some hard-to-find like the Ogiva in celluloid (another classic design) and several other hard-to-find OMAS pens, but you have to pay for it, I never have bought something from that store, but as soon as I get a lot of money I will try

Another great option is Stipula, you can t go wrong with it. I am the very happy owner of three celluloid Etrurias (one with retractable nib), one Cromo and one Saturno (both in hard rubber), and I am really happy with all! Nibs are from Bock in Germany, but tuning is made in their Florence factory (some details about this company can be found in [url=http://www.marcuslink.com/pens/stipula.html)], all my Stipulas write great, with very good amount of flexibility and nice juicy strokes, also this company offer factory stub nibs, that are a pleasure to write with.
And also there are the always reliable Auroras, with very nice design, and great nibs. The regular nibs (F.M and B ) are a little bit scratchy along the first pages, but later (when they break) are really smooth and reliable (fast starters etc), and the factory special nibs (oblique and italics) are smooth out of the box, not very flexible (not as much as OMAS or Stipula) but very good writers.
So your three options list will be (in my 2 cents):
OMAS: old style Paragon or new Milord, in celluloid, the Arco is my favorite.
Stipula: any celluloid Etruria, with stub nib (you won t regret)
Aurora: Optima in celluloid, if you can, go for a oblique.
If budget is a concern,
OMAS: Paragon or Milord in vegetal resin (also called cotton resin) the OMAS resin is a close relative of celluloid, with a very pleasant touch.
Stipula: a Novecento in hard rubber, also with stub nib, you can find it in the Regina Martin auction page, ask for the stub nib, she will get it for you.
Aurora: modern 88 or Talentum, the first one with piston feeder and the last one with c/c.
So, please let us know what you got once you make your mind, and (if possible) share some picts!
Very best
Ricardo