Puntapete: I generally sit back and read what everyone else has to say. Usually I have a considerable amount of humor associated with what I read on these forums. Some postings are from people that have a genuine love of their boats and they take great care to do all the upkeep to keep them nice. Others are more along the lines of the self appointed experts. You'll have to do a lot of reading in these forums to know who is who.
I started out as a youngster sailing an AMC Sunfish. Later on I owned a Catalina 22 and now I have a 30 Islander Bahama. All of them taught me something about sailing. With that said I'll offer my humble opinion. (and I don't claim to be an expert.)
The sunfish was great for getting the basics. The downside was that it was not something I would go out in when the wind went above 15 knots. It was also a great way to stay wet so it wouldn't be my choice in colder climates.
The 22 was great as a day sailor and for some overnights. It was small in the cabin but since I'm only 5'7" it was cozy. Based on your size I would discourage you from a boat without adequte headroom.
The 30 is actually easier to sail than either of the other two. It also gives me the ability to sail year round. It is a great family cruiser BUT is by no means a boat I would take on an extended cruise and I'll be upgrading within the next 2 to 3 years to a blue water cruiser. (since I've now owned several sizes of boat I feel much better about my abilities to judge what I need in a cruiser.)
With that said I think you have a basic problem "TIME" as in you don't have a lifetime of it to learn what you need to know. Your only option, as it appears to me, is to, A. take a costal cruising course and, B. plan on getting the bigger boat. BUT---make good friends with someone that has that lifetime of experience and listen carefully and strongly consider their judgement when buying the bigger boat. DO NOT let the writers of an internet forum be your reference source in this situation. Don't get me wrong, these forums are a great resource and there are some very knowledgable people that frequent these boards BUT there are also way to many "self appointed experts" that will offer opinions and not being able to see them in person and have a conversation with them is a terrible handicap when trying to decide if they know what they are talking about and if their opinion is valid.
With all that said I would offer 2 pieces of advice.
1. SHOP SHOP SHOP.....spend all the time looking at boats that you can BEFORE you decide on the one you will purchase. You'll see lots of "stinkers" that brokers will try to pass off as great boats and you'll see some real gems that will show obvious pride of ownership.
2. Spend time at any marina you can with a lot of boats and don't be shy about offering to crew on as many boats as you can. You'll gain some very valuable sailing experience as well as learning about many of the features that you will ultimately want on you boat.
Just my 2 cents...........
Fair Winds to all