An attempt to give some direct answers
At this point I think we have made it pretty clear that the "best boat" does not exist. If I were looking for an offshore boat, I would tend towards the Tartan in the list of boats you mention, but there are many others such as Caliber, Island Packet, Tayana, Hans Christian, Amal, Morris, valiant, older Morgans and Pearsons, Shannon, and on goes the list. The boat market is packed with boats that you probably haven't heard of that are great candidates.Size is difficult to recomend. Some swear by their 45 footers, but I wouldn't want one for a number of reasons - I prefer the mid 30s. The Pardeys lived aboard a 26 footer for years, travelling the world without even an engine. Do you gotta have a TV and air conditioning? I don't, but I gotta have a good stereo and a guitar. Some people long distance cruise w/o a refrig and live on 12 volts. I could handle the 12 volts, but I gotta have cold beer. On electronics you asked about the bugs and yes, they are pretty much worked out. I don't think US companies are the only choice, but I would buy from a well known company. For ocean cruising, auto pilots should either be wind vane type or below deck installations as both are a bit more robust than the above deck units. There are a few direct answers from someone who has only cruised the Great Lake. My longest trip being 3 months. You will soon see that, now that I have offered my opinion, it won't take long for someone else to disagree with me. That is the nature of sailing and part of what makes these boards fun.