Go for it Norman!
About the GPS weight ... i think he used one of those 5.5 ounce Garmin's, and also superlight lithium batteries, which are like 1/5 the weight of regular batteries i think. So the total weight would be around 8 ounces i think , maybe a bit less or a bit more -- not bad. (Check out those lithium's -- Wallgreen's has them -- definitely more expensive. You'll be amazed by the weight difference).