Back in the 80s, I was sort of a machinist, most self taught on the job. For the most part, we used High Speed Steel drill bits for drilling all kinds of stainless steel, never seemed to be a problem. So, years later, I've personally never found a good reason to buy anything any more expensive then high speed steel drill bits.
Most stainless steel really isn't that hard, or that hard to drill. Get the speed right, use a little cutting oil if your drilling through something thick, you'll be fine. Larger diameter drills requires lower speed than smaller diameter.
Hardest drilling job I ever did , was putting three 0.030" holes through three of the points of the 1/8th inch hex heads on 1500 small bolts that were being made to go on a F-18. Only drilled my finger once during that job... ( and never on any other jobs ). If I was lucky , I could get about 30 holes drilled before the drill bit broke, or I had to go sharpen it. These were wire holes , on the small bolts. Thankfully, I only had to do that particular job once... It was easier than digging ditches or bailing hay though. The most amazing skill I learned on that job, was how to sharpen a 0.030" drill bit... of course I probably couldn't do it today, as my eye sight just isn't what it used to be.