chilli con carne beans - which seed (variety)?

Hi, I'm new here (I live in the uk, am friendly, have two allotments and am a compost nut)...

A friend has asked me where he can get the proper seeds to grow for his chilli. But what are they? As far as I've been able to find out they are what we call collectively - French Beans - Phaseolus vulgaris. And while I'm sure my friend could use seed of runner bean - Phaseolus coccineus - or any bean I guess, I thought it would be interesting to try a bit of research.

From wiki: Kidney beans and other beans such as pinto beans, navy beans and black beans are known scientifically as Phaseolus vulgaris. They are referred to as "common beans" and they all derived from a common bean ancestor that originated in Peru. Red kidney beans are universally used in New Orleans and much of southern Louisiana for the classic Monday Creole dish of red beans and rice. They are a common ingredient in chili con carne. The alubia pinta alavesa, or the "Álava pinto bean", is a red variety of the pinto bean (also used a lot in con carne)

So does anyone really know a good one that's readily available from somewhere? (I am in the uk)