I'm not sure taking antibiotic proactively is the best idea as you can contribute to antibiotic-resistant bacteria and also become sensitive to it (as I did with an antibiotic related to Cipro after taking it for a long-running recurring infection). Avoiding meat won't preclude food-borne illness as fruits and veggies are just as often the culprits, whether due to contaminated wash water for uncooked items or cross-contamination post-cooking, for cooked stuff.

I mainly rely on bottled water but also have one of those portable water-boilers to use if I run out of bottled. Though nowadays luckily it's easy to find good bottled water even in more remote places. If the tap water is drinkable though I just use that unless it tastes bad.