holy thats low. your 10lbs less than me, 2 inches shorter. and only 8? def get some bigger bindings on both. like the STH 14 driver as mentioned. i'm getting a pair of those for my Green Lifes, and since my old STH 16's are destroyed(Had since they came out). i'm replacing the 16's with the 16 steels. for my one lifes.
now i hope you do alot of big mountain skiing, as do i, so my din is at 11, since some landings arent the best. my friend who is probablly 5'9". or shorter, and 125lbs, his is also at 11 for din.
the bigger bindings with help alot.