Tiger 800 Rear Tire Size For 900 Gt

Many have used a 110/80R19 front tire on the 900 GT due to the lack of a radial in the stock size. I have been using that sized Continental Trail Attack on my bike with no problems. Now it's time for a new rear and the front still has plenty of life. Finding a 150/70 is proving to be difficult at a decent price. Has anyone used a 160/60 for a rear tire without problems?

As a side question, have any of you had experience with the Shinko 705 ?