Hi p.f.,
First of all, welcome to our little fountain pen nut house on the digital prairie!
Regarding your question: if you want a Pelikan nib with line variation, you would have to order one from one of the nibmeisters, like Richard Binder. The line variation a Pelikan OM nib offers doesn't come even close to what we would call a stub nib here. it actually is only a nib with a slightly angled tipping surface, to allow left handed people to write a little easier with fountain pens. IOW, it is an M nib that requires teh pen to be held at a different angle than most people would normally do. With any of the broader nibs, like the OB and the OBB, it is even worse: no line variation whatsoever.
Here is a link to Richard Binder's site:
Richard's Nib Page. Other suppliers are Pendemonium:
Pendemonium's Custom Nibs, and Richard Mottishaw
Richard Mottishaw's nib pages. AfAIK, all of these people allow you to buy a bib from them and have it reground to a shape you like.
I think our own Dillo could probably help you out, too.
HTH, warm regards, Wim