Thats a tough one at your specs.
If at all possible go out and paddle them and see what you like the best.
At 150 pounds you could easily paddle the 59. It will probably track a little better and might feel a little more nimble.
It may be a touch easier to roll for you because it is narrower.
AT 5' 11" tall you can deal with the higher deck of the 69. It will float you higher and therefore be a more forgiving river runner
which will allow you to paddle harder stuff.
I think both will surf fine for you but the smaller one will be easier to edge possibly.
Good luck and I think that either will be a great boat for you.
later
Shane