This week's book giveaway is in the General Computing forum. We're giving away four copies of Arduino in Action and have Martin Evans, Joshua Noble, and Jordan Hochenbaum on-line! See this thread for details.
There's no one right answer to the question, although here's a quick comparison chart from the JavaRanch Faq: JDBC Driver Types
In theory type 2 would be better, but I suggest you run actual performance comparisons on the types of queries and data you expect to run. There may be other issues such that the performance difference is negliable or possibly worse for using type 2.