I think I have a great ally — my A&P 2 professor (also the head/chair of science department at our CC) has been very supportive of my aspiration for med school. He gives me his inside thoughts on which professors will be better suited for my type of learning (as in Chem, he said one instructor was from a more engineering/chemical background and he felt less suited for me vs another from a biology background) and which courses at the CC are not as “rigorous” as the University, etc. I’m considering asking him for a LOR - as he’s been so helpful and really stimulated my interest and confidence so far …But when exactly do I ask him? And if he were to write it soon, where does it go for the next couple years (till I actually am in the application process)? I have his wife for my microbiology course this semester – I know it’s not requied, nor would it be transferable to a 4-yr school should I decide on a second BS degree – but she’s equally as enthusiastic as her husband and it makes it a joy to learn! Anyway, I’m hoping that a LOR from a Chair at a CC be as valuable as from a 4-yr university …

Some people have used the letter service Interfolio to keep their reference letters. That way they can still be “blind” (you haven’t seem them) but you can get them written and safely filed away for application season.

So, should I ask him now for the LOR and just keep it with the letter service for the next ~2 yrs? Or, should I wait till my time at the CC is complete? I anticipate our rapport to continue for the next few semesters …

When do you want to apply to medical school? Most med schools want good, but recent, LORs.
However, many premeds are wary of waiting too long after they have taken a class before they ask an instructor for an LOR. There is the fear that the prof will forget them (the student) and their work/grade. Or perhaps the prof will leave the school, or, unfortunately, die. One way to get around this is to ask the instructor for an LOR NOW, when they have a good idea of who you are and your competency in their class. But don’t mail it, just keep it to yourself (sealed) or send it to the letter service. Then when you want a new LOR from the prof, show them the old LOR to jog their memory. Or have the letter service send it to the professor. If the professor has left the area or retired, you may have to track them down, or get LORs from other instructors. If, in the unfortunate situation the prof has died, you still have the original letter, although it may be awkward to send it and its post-mark won’t match the date the letter was dated.
If you wait too long the professor may have forgotten about you, and will rack their brains trying to come up with something nice to say about someone they vaguely remember.
Getting more than the minimum number of LORs may be wise in case a situation arises in which you cannot send it; you will then have backup LORs that you can send.
Another point: some letter services have time limits on how long a letter can be in their files before it is purged. Others charge a fee for each letter sent or for each year your account is maintained.
How recent is “recent?” This is up for debate; I was told not more than a year. Other ideas and recommendations?