Where to get pre-approved? Don't know where I'm investing yet.

[David Soria]

In my experience, I've come to the realization that I need to get pre-approved, rather than pre-qualified, in order to get someone (real estate agent) to show me around an area and start helping me find a property I'd like to invest in. 

The problem is that I don't know where I want to invest in yet. I live/work in South Orange County California and with only ~$40k to put as a down payment, I don't have a lot of options to buy. Ideally, I would like to buy something in my area to house hack, but that's still hard. I was looking at Las Vegas for investing, but want to keep my options open. 

Is there a "best thing" I should do in terms of where I go to get pre-approved? I want to avoid having to go to different places in different areas to get pre-approved, each time getting a small mark on my credit history. I don't want to limit myself by getting pre-approved at a bank in my area and not being able to use that pre-approval in another area, or vice versa.