Personally, I think the best BPO product is Proactiv's Repairing Lotion (2.5% BPO). It is gentle, but effective. It also has a very high quality formulation, and it's the only BPO product I've used that absorbs into your skin completely and doesn't leave any red marks. I beleive you can purchase it separately from the rest of the kit on ebay.
I didn't have too much luck with Paula's Choice Blemish Fighting Solutions for several reasons. One, they were too liquidy and runny. Two, they had a kind of weird scent. Three, I think the regular version wasn't too effective on me (2.5% BPO), and the Extra Strength version (5% BPO) was TOO strong - it made my face sting!
I've never had to use a moisturizer with Paula's Choice BHAs. In the day, the 1% is moisturizing enough for me, and at night, the 2% liquid is fine as well.
However, I have heard good things about Paula's Choice moisturizers. You can always ask for free samples of all of them to try them out yourself.
In drugstores, I hear Complex 15 is good too.