Parts are pretty cheap and lots of aftermarket accessories available.
For the years, I'd go with any year but 87. Only because it had a cdi that was prone to failure. Bikes 2000 and before have both kick and electric, in 01 they dropped the kickstart and added the disk brake.
The TDub can do almost anything off road but the stock front tire (known as the deathwing) doesn't do so well in mud and washes out a lot.
60-70 I personally haven't taken mine above 40 in my week of ownership.
Hope this helps!