I got into fountain pens a couple of years ago. All mine are cheap Chinese pens from Ebay.
My favourites, all clear plastic where available:
Jinhao 992, very cheap but good quality, smallish but fits perfectly to a A5 notebook. Comes with cartridge converter.
Wingsung 3013, heavier and a bit bigger, vaccum filler, I think a copy of the Twsbi vac filler.
Wingsung 3008, piston filler, like a cartridge converter but built into the pen.
Jinhao 51a, based on the Parker 51 hooded nib pen, comes with cartridge converter.
Hero 616, has been made for decades, exact copy of the Parker 51, inc the rubber ink sac which you squeeze to refill.
Delike Element brass bodied pen.
I started off with the normal Diamine fountain pen inks but they are completely non waterproof and I don't use them anymore. I now use "document" inks which are permanent, and are "waterproof" by fountain pen standards.
The first is Diamine Registrar's iron gall ink which is an interesting ink which reacts with oxygen changing it into a water insoluable ink. The ink I mainly use is Koh-I-Noor Document Ink which reacts with the paper fibres.
You can reshape the nib with a fine diamond stone and/or abrasive papers if the nib is not to your liking, eg into an italic from the the usual ball tip, or a fine from a medium, or just to make it smoother to write. Or even more flexible to get line width variation.