HI @Collin S.. You can pick your contractor but they must be licensed and insured in the type of work they are doing. But, I would suggest getting a few suggestions from your lender since they are probably familiar with a few contractors from having gone through the process with them. Some contractors understand how the 203k program works more than others. It's my opinion that you'll want to be sure the contractor understands the 203k process and how important it is to do things the right way at each step. Plus you'll want to be sure the contractor understands the payment process.
Also, let me know if you need help with finding properties or a lender referral. I've helped some on here and would be willing to assist you also.
Inventory is low but there are a few duplex properties out there. I showed a couple this past weekend. Not in your zip codes but rather at the beach. There's one that just hit the market in Riverside that I want to go check out. That would be 32204.