If you'd like a list of builders in these specific areas, write to me an e-mail address and I'll send them to you.
Keller Williams Realty
I have been working with a buyer in the Natomas area who is looking at new homes for the last couple months, and we actually just found them a property. Literally it seemed all of the builders we looked at are offering incentives and will accept FHA financing, which as of right now is 2.85% down. Many have their own "in-house" lenders or perferred lenders, but their offerings for financing are going to be in line with what you will find by seeking out your own loan officer and loan program. The difference with using the builder's preferred lender is that as an incentive to use said lender, they may offer to pay your closing costs or $X toward upgrades. They may also offer to buy down your interest rate to a below market rate. Your agent can assist you to negotiate these terms as well.
As Sue stated, you are best suited to go out and visit these communities directly. Keep in mind that these communities generally have Mello Roos, Homeowner's Association Dues, and future (if not current) flood insurance requirements. My belief that new home buyers really do need assistance from qualified real estate professionals has been thoroughly reinforced lately while working with the Natomas buyers I mentioned earlier. While some builder sales reps are knowledgable, many are not knowledgable or qualified to answer many buyer questions. I found that most don't even know what Mello Roos are, many can't explain what is and is not included in the HOA dues, don't know the difference between Mello Roos and HOA dues, did not know of flood zoning status, etc.
Good luck to you.