I know this an old post but I wondered if you settled on something. I too would love a 30 with my 32 for the steep climbs. What did the OP end up getting?Praxis Works Alba Crankset 48/32T, BB30 only (?), $175
This is named after the road that is inspiring me to find a solution. If I could fit it on the bike, I would buy this, as it is local, named Alba, and the company is well-regarded. Alas, it seems they only make bb30 stuff, unless I really missed something.
I found this link with some similar listings last night:
Low Gear Range: Road Shifters & Gears For Easier Hill Climbing - CyclingAbout CyclingAbout