I'd get a Bus or a Thing or something like that Notchback (I don't care for the Fastbacks, Squarebacks or 411s) the problem is rarity and price. The bugs are getting expensive but they are still plentiful enough. There are no pre-68 busses out there that are reasonable and I like the 68 & 69 but not so much after that. Karman Ghias are ok but they look a little...
The 67 had a 1500cc single port engine in it. In my 67 convertible I put a 1600 dual port engine in it which was the biggest factory bug engine they made. The 67 was also the first year for a 12 volt system which meant easier starting and brighter headlights. The 1966 was more of a "one year" bastard with a 1300cc single port engine in them. They had a "1300" emblem on the engine lid. My first bug was a 66. If you consider the difference of 300cc between that 66 bug engine and the 67... that's like adding a small motorcycle engine to it. That 67 was a lot quicker.