To answer your question on the stylus, the first picture shows a cartridge and stylus. The stylus is the bit with 3E written on it.
You can buy Ortofon OM styli separately, but I've found that generally they are sold as full set of cartridge and stylus, and separate styli are no cheaper really.
So look for the best stylus you can get regardless if it's with a cartridge. Then you can swap the stylus only, if you want to avoid realigning the cartridge from scratch.
I would get an OM10 (compatible with OMB cartridge) for £50 ish. It's a bit better than the 3E or 5E for a similar price. You need to spend double that at least to get a better OM stylus, unless you change the cartridge type altogether, but you will need to check it's suitable for that tonearm as Airhead says.