Some of the Privateer Press Cygnar Warmachine models might work for you (the Sword Knights and Precursor Knights specifically), and there are a few in the Iron Kingdoms model range too (which you can often find lurking for cheap in many olny stores). The Protectorate range has a huge number of knights and paladins too. Note that Privateer Press do have a parts-ordering service that's excellent if you are in the US (and still excellent but pricey if you aren't), so you can just order one figure if you want.
If you are after quantity and more realistic scale, you could try looking at the Perry War of the Roses boxes, as well as Fireforge Games' offering. These between them should allow you to make just about any fighter, henchman, thug, or knight you could want to make - and all in plastic, and all pretty compatible. Might be too much of an investment for one or two models however.
Heresy Miniatures also have some fighters and paladins, are currently having a 25% sale.
Hasslefree Miniatures has a few good female paladin fighters too.