My experience was similar to TakeruK's. When I was contacting POIs, I had one that said something like "I am not taking any new students because I'm planning to retire in the next few years, but please feel free to ask me questions". It seems like an issue an older professor would be aware of. I'm not an expert, but if it doesn't come up before, it seems like something for you to bring up later in the process, when you've been made an offer or when it's likely you'll be made an offer. That way, it doesn't seem presumptuous. Consider asking a professor you trust about how to ask such questions. Good luck!
I recently found this place. I just submitted apps to a couple of quantitative psychology programs. I discovered quantitative psychology through taking an undergraduate measurement course and taking a boatload of stats courses. I was able to go to Psychometrika this last summer - a definite must-do if you're into this sort of thing! Beyond that, no advice - just happy to see others doing/trying to do the same thing