I'm in Colorado and just bought a home over the last month. I went with a service called Accept Inc. You basically go through the underwriting process first, they then buy the home you want in cash (Giving you a cash offer to the seller), then you do a traditional mortgage to buy the house from them. No mark up.
Sounds great... but I can tell you that having a cash offer didn't mean anything if you weren't the top offer. I lost out on many homes because I didn't come out on top. Lost against those with conventional loans too. People will wait an extra 2/3 weeks if it means an extra $10K in the home price.