So I've been pricing things out and weighing my options.
A steel roof is out of the question; it'd cost me 4-5 times the cost of regular shingles or some of the other options. I could swing it financially, but would get way more bang for the buck if I spent that $$ on other improvements we've been holding off.
I've essentially got two options I'm considering now for the "low slope" parts of the roof (marked in yellow above)
OPTION 1) Ice & water shield the whole way up, with really good quality (35yr) asphalt shingles. Because of the low slope, no warrantee would cover the shingles, but I'd have 2 layers and I'd feel pretty safe. My neighbor did his this way and is very happy with it.
OPTION 2) Bakor LowSlope "peel & stick" 2 ply roofing
http://www.can-save.ca/index.php?option=com_content&task=view&id=235&Itemid=202
This stuff looks promising, and is guaranteed for 20 years. It would only cost 20% more than the ice & water shiled + shingles. It would also be WAY less labor to install. My only concern is that it's a relatively new product.
Any thoughts?