Sounds like you had a great trip, and the gear you had worked great for you. Keep looking for that lighter tarp, and you'll eventually find one; until then, use what you've got.

It sounds like one of the better things you did on that first trip was plan well: reasonable mileage, and good weather. Quite honestly, the shelter you have might be a bit iffy in prolonged blowing rains, in an exposed campsite. But, if you avoid those more extreme situations, it will work great. You will probably change your mind as you get more trips behind you, and you may work through three or four bivies and tarps until you find the one that's "just right," but that's OK; you just use the spare gear to get other folks out on the trail with you.