A few comments:
– I hope you take a moment to appreciate what a wonderful position you are in as a result of your successful family business. It sounds like you are getting wonderful work expereince and are on a pathway towards a successful future – learn from those who are at the company. You may want to work during this important juncture with an IPO coming.
–You do not “need” a top ranked MBA to successfully lead a company. In fact the best/smartest CEO my husband worked for (he has been a CFO at a few large companies) never finished college and simply worked his way up from an entry level job.
–Some level of education might help to establish yourself among other executives there and fend off whispers of nepotism. Finishing your BS degree must come before even considering a MBA. I would recommend finishing your BS at some point – if you want to keep working you may want to finish it up part-time at a school closer to home.
–To get into any top MBA program you will need the following: 1) completion of a bachelors degree with an excellent undergraduate GPA 2) very high GMAT scores (some programs now take GRE scores as well) 3) outstanding recommendations 4) strong essays 5) typically 2-5 years of meaningful work expereince with increasing responsibility. In and of itself, being “heir” to a successful business won’t get you into a top program.
–In lieu of full time MBA some top business colleges (ex. Harvard extension, Wharton executive education) offer professional development courses. And depending where you live, there are some excellent Executive MBA programs structured to allow people to work full time and attend class over the weekend/summer (Wharton, Columbia, and Yale have such programs to name but a few).