How much money do you have for maintenance? The air cooled Porsches, while more desirable, are real maintenance hogs, and tend to cost more to repair or modify.
Better in the long run? Not sure what you mean by that. Box is an all-around better car, but I still like driving my '77 911 w/ '87 3.2 L engine and it gets way more compliments than my Box. I wouldn't drive it year round in your area. At 150k mi its due for alot of suspension work. If it's been used year round I wouldn't want to climb under that thing.
Engine was rebuilt 50k ago, new clutch, new starter, less than 10k miles on shocks, new tires, new shocks, replacement seats, top done 3 years ago, paint/interior are fair (7/10).
Rblt engine can mean anything/nothing w/o receipts. Shocks are the easy part. There are rubber bushings front and rear - big job. W/O receipts, the first thing I'd do is re-do the brakes - from pedal box to m/c to calipers. Another big job. Does the a/c "work"?
I'm with BRP, The 986 is going to be a more refined, better driving car. Looks are subjective and I happen to think that all Targas are lacking in that department. A late 80's sunroof coupe would edge out the Boxster on looks and style in my book and properly restored would be a great drive if not a bit less forgiving. The issue is that 34 year old rubber with 150K of service is likely in need of replacing as are many other components. These cars are infinitely rebuild-able, but you need to understand that they do wear out and you may be on the hook for some serious maintenance in the future. The Boxster is no spring chicken either, so while not an apples to apples comparison, No one can really say that you won't be dealing with a similar scenario with that car...