I've made FPs from two kits - CSUSA's Artisan, and PSI's Big Boy. I selected these kits because they use 10mm tubes - one of the things that I promised myself when I started the penturning adventure is to focus on a couple of diameters so that I don't have to have a multitude of drills and barrel trimmers.
The Artisan offers 10k gold plating, while the Big Boy only comes in 24K gold. I've never seen a kit with gold T/N, black T/N or rhodium. That's something I don't understand - FP users are accustomed to paying more for quality. The pen kit makers don't seem to understand that they are missing an upsell opportunity.
The Artisan is a snap cap. That's would not be my first choice. It also doesn't come with a converter (nor does the Big Boy), and I don't believe that CSUSA even offers converters (PSI offers two versions - standard, and 'better'). And the Artisan has a metal extension on the end of the body that I really don't care for. However, I think it would be possible for an experienced turner to do a closed-end version. One thing to be prepared for - it is necessary cut a shallow notch in the cap to accommodate the clip. I use a Dremel, but a small file would also work.
The Big Boy has a screw-cap. It's a bit bulkier than the Artisan, but for me that's not a problem. The end of the body also features a cap, but it's nowhere near as long or ugly as the metal cap on the Artisan. However, the Big Boy does have a hexagonal ornament on both the cap and the body end that looks a bit 'industrial' - some may not like it. The Big Boy has a rubber o-ring on the body to prevent leaks in your pocket - the thought is noble, and it's not all that obtrusive. Another thing that some users may object to, and I suppose you could leave it off if you prefer.
I also have an El Grande that my wife gave me a couple of years ago (before I started turning). It's a nice design - there is a plastic extension on the body that I don't really care for and that could be omitted by doing a closed-end version. Its a screw cap without a lot of tacky ornamentation. But it's a tapered design - the body and cap use different diameter tubes. And the version I have has a rather fine nib. I suppose that it would be possible to find a substitute nib. I will say that it writes better than either the Artisan or the Big Boy.