I use two -- for smaller batches (about a quart) a Cuisinart 400w stainless steel model with detachable head; it's been an amazing workhorse, going on 2 years now. For larger batches (up to a gallon) we use a Waring model... not sure which one but it's one of the smaller units. It works just fine and has two speeds.
I use Sunbeam plastic one. Brilliant and cheap and doesn't leak oil, I don't like the metal ones as they change the temperature of what you are making quite rapidly especially working on small scales like I do.