I would second the 69 but both boats will work for ya. I'm a similar size and I like the 69 because it's skinnier but I know smaller guys who paddle the 79 and like the extra volume and length. At our size self-supporting out of the 69 requires going extra light, but you can make it work as I've taken it down the Clarks Fork Box and it paddled great still. Forcing you to go extra light makes portaging it way easier also. For me I just have better control of the slightly smaller 69 but the 79 will be slightly faster and better when loaded.
Cub boater: "What do the spiders mean?" Old fart boater: "Trust your intuition." CRCII