I'll be flying out to Panama (200 bucks round trip!

My ability: Is one of a beginner, I've surfed some and loved it. I've grown up sailing Hobie Cats, Wakeboarding, and Water-Skiing, so I'm definitely comfortable in the water and passionate about its respective pastimes. But I just haven't found the right time to get into surfing until now. I honestly feel like this trip is a great opportunity from that standpoint, it gives me the chance to really live and breath it for a couple months.
My dilemma: After looking at how much it costs to rent a board for a two month period I'm now on the hunt for a surfboard/s that travel/s well and is decent for a beginner. Going out and plopping money on a brand new board is just not my style. So craigslist is where I'll probably be looking unless I get pointed somewhere else. So, the airline says that I can take two boards with me on the plane with a length no more than 115 inches (292 CM) and weighing no more than 70lbs (31.75 KG). I own a a crappy costco Wavestorm fomie that I've messed around with, worst case scenario, it'll be one of the boards that make the trip. My first thought was to take that and look for a potentially smaller board to take as well. But to be honest lugging that thing (Wavestorm) to a foreign country seems kind of ridiculous. On top of that, everywhere I look I see the "Don't try and learn on smaller board!!" command and I understand it. I have no misconceptions about "looking cool", I'm going to look like a complete idiot out there, period. But for weight/travel purposes getting a smaller board would be smarter and the other variable is my younger sister (age 15) will be joining me later on, so a smaller board might be better for her as well.
Finally!
My question: All this leads to me having a lot of confusion and not a whole lot of time to figure it out. I think getting a shorter 6'8"-10" board with a high volume/width (for stability and ease of paddling purposes) would be a good idea. It would give my sister something to learn on and give me something to aim toward. Long story short, I want to learn, I want to have fun, I would also like to look as little like an idiot as possible. What should I do? What board/s should I get/look for given my learning and travel constraints? What would be the best possible board combo for a trip like this? For reference I'm 5'9" and weigh about 135-140, age 18 and athletic. Thanks again for your patience and insight.
PS: Mods if you'd rather move this to the travel section that's fine wasn't sure which board to post in.