As far as safety, in the opinion of most, the boat and the sailor are more critical than the size of the boat. That being said, larger boats have an easier motion and will tolerate stronger winds and higher waves more easily.
Next it comes down to your personal tolerance for small spaces. I have met two couples living on a 27' sailboat that were happy with the space and one couple that thought 41' was too small. Anything much under 30' it gets a little more difficult to store enough food, water, tools, etc for weeks. Not impossible but more difficult.
If you're going 30' probably need a bare minimum of 20 HP. A little more would be better. Inboard diesel is the preferred option.
Thanks for the info. I am not in a hurry so i can wait til the right one comes along.