Our (general-ish) masters program doesn't automatically admit/match students to/with particular faculty, but a thesis is required. I've had several absolutely outstanding masters students who contacted me prior to enrollment or soon after, took initiative and really learned and were productive in my lab. These students are now in very strong doctoral programs or well on their way to becoming highly competitive. I've also had masters students who don't seem to understand that their courses plus a token effort in lab are insufficient preparation for a doctoral program. I guess what I'm saying is that if YOUR goal is a doctoral program, reach out to faculty, work hard and show initiative. There are no guarantees in the current doctoral application climate, but you can really boost your chances by basically acting like a doctoral student already. Unless the lab really is at capacity, I've never known a faculty member at my institution to refuse to take on a strong student who is motivated and willing.