I also work in a professional office setting, I started biking in the summer last year, and I'm basically a blazer addict. First step is to pack your blazers so they don't wrinkle:
http://lifehacker.com/5936489/the-best-way-to-fold-and-pack-a-suit-jacket.
Second, would "ankle"-type pants work for your body type? Something like this,
http://www.thelimited.com/product/lexie-collection-ankle-pants/369357321440700.html, though obviously that pricetag is high. I've bought pants like that from Goodwill and been pretty happy with them, and they're very professional (at least in my workplace). If not, I see two options: (1) stick with skirts, either biking with them or packing them by rolling, or (2) get center-crease pants, fold on the crease, and pack by wrapping around your folded blazer. The center crease means that the inevitable fold lines work in your favor.
Capsule wardrobe: My suggestion would be 3-4 pants/skirts, 5 shirts or shells (I'm a big fan of shells; sleeveless is great for biking and they somehow look *more* professional than a shirt under a blazer), 6-7 blazers and some broaches, statement necklaces, scarves, etc. Make sure everything "goes" (i.e. either black/grey, blue/grey or blue/brown) and that you get enough variety by mixing stuff up.
I have bought enough from my local goodwill to actually make that capsule wardrobe, so you don't have to spend a lot to get there, but you do need to be somewhat patient, depending on what your local thrift stores are like.
