Our weekly dives are in the evening, usually meeting up at about 6:30 pm, so maybe they'll be doable?
But yes, I would purchase a drysuit at the very least when you can. Expensive, but they're so worth it! Rental fees add up quickly. Check out the classifieds section here or Craigslist for used stuff. I would have no problem buying a suit (with careful inspection), tanks, or weights used. Or all of the shops around here sell new suits and equipment.
Come to the nerd side, we have pi!