For 150 sf, I would use a manual nailer. It should take no more than a day for the whole job, trim and all. As for nails vs. staples, i feel both would do an adequate job to hold prefinished flooring in place. I feel that a manual nailer will easily give as good a job as pneumatic for the job you are doing. To avoid cracking during installation and shrinking after, make sure you purchase the materials at least two weeks (yes, two weeks) prior to doing the job and allow them to adjust to the humidity levels of the room where they will be applied. Best of Luck.