I passed your query on to one of our electrical sub-system mentors.
Our electrical group mostly use the ribbon-style power resistor with a fan blowing on it. The ribbon style are easier to get, cheaper and take a lot of abuse. Between Ebay and online surplus vendors, this can be done on the cheap.
http://www.milwaukeeresistor.com/pdf/ribwound.pdf
There is a chassis mount style which one of our electrical mentors has used at work as well. These are aluminum cased and can be mounted to a finned or water cooled plate, but are more expensive.