I recommend renting a car, there may not even be a bus with direct service to Boca Grande. Also, it is a long way from the NW part of the island to Boca Grande on the SE coast. I would call down there and get their advice about kites. The wind can vary although most of it is from the trades. The thing about the Huts is it is offshore and gusty with land wind shadow effects. Boca Grande is largely clean wind off the ocean. BOW kites likely help a lot to tone down the gust range at the Huts compared to the old C kites. The first time I was heading down but had to cancel on the day of travel, winds were into the low 40 mph range at the Huts! Trade winds into the higher 30's weren't that uncommon at various times of day not too far off in Bonaire. When I actually made it to Aruba, the winds were a lot lighter, mainly below 20 mph, even down close to 10 mph at one point. I would call these guys and see what they say for your time of travel. You might even be able to rent a larger board for the Huts to help things out.
http://www.arubakitesurfingschool.com/
http://www.kitesurfingaruba.com/
Have fun down there!