Where did you get the tool bag from I have been looking for one that the down spouts would fill out the bag but the ones I have measured would leave a gap on the ends I use one now with pvc but the difference in wieght between pvc and the down sputs is worth making new one.NICE JOB!!!!!
I picked up the box at Menards, a local hardware store. I think the cost was about $20 bucks.
The gutter I used is that square plastic stuff. I had some just sitting in my garage. You're dead-on about the weight. Originally I was going to use pvc but the weight was an issue. You also gain space with the square gutter. I'm going to put another one together soon.