when I feel the need for caffeine (which is pretty much every morning) I have always been a coffee drinker, but I quit that for good about 3 weeks ago. I am still having trouble waking up in the morning, so after breakfast I'll usually have a small glass of iced tea, and that seems to help me wake up.
I also have low blood pressure, and I've never noticed a connection with caffeine, but I do try to make sure I get enough salt in my diet.