Look, a lot of the "think of future needs" arguments are blantant over-engineering. KISS.
The only thing you need to do to address future needs in this respect is to simply write your logging routines in such a way that it is easy to totally redirect it later to something else. DIY text, syslog-type services, or a DB. Keep that concept in mind, but DON'T write anything but what you need right now.
From what you described, it absolutely sounds like you should just use a simple text file.
