pretty much any carbide coated drills will be fine, depending on the type of stainless but i'm sure your not using anything to wierd (some stainless is sorta gummy when your machining on it). also like stated use some good cutting fluid and it will help clean out the chips and extend the life of the cutter.
we had to drill 2000 holes in some beams and we used those hougen bits, are you using the center? if they arent guided they dont do to well, and will chip/break
if your doing this in a mill or have one available you can use an insert tool holder. they are more expensive initially but you can jsut replace the inserts when they wear out as opposed to replacing those drills all the time.
something like this
http://www1.mscdirect.com/cgi/NNSRIT...-SearchResults