Like others have stated, the 1/2" tube is probably not really needed.
As to your question, I would reccomend the external pick-up. The internal pick-up tube is long and prone to breaking where it threads into the block. I went to the external pick-up after breaking 2 of the internal. I believe that normal vibrations and wheel stands contribute to the tube failures. For the record, both of my tubes were 1/2"..