All of my pen models can be made into a bulb filler, with the exception of the Herald.
Whether or not the barrel is made from a translucent material, making a pen into a bulb filler adds $100 to the typical cost of a cartridge/converter pen. This means typically $350 with a steel nib, and $450 with a gold nib. Email me if you are interested in an exact quote.
Below is a quick video showing how a bulb filler fills....
And here is a slideshow showing bulb fillers that I've made. If you see a pen that you like, click on it to see a description. Or click here to see the entire set of bulb fillers on SmugMug.