A Solo 401(k) is a qualified employer retirement plan, and needs a legitimate business activity with no full time employees to act as a sponsoring employer.You can read all day long on BP and get into paralysis of analysis, as well as digest some less than accurate information on the topic, to be sure.Alternately, you can read up a bit, with the goal of identifying a few professionals in the field, and then get on the phone. 

I haven't gone all out and really dissected a lot of states to potentially invest in, but since Vegas is close, rated #1 for growth as per Realtor.com and now has 2 professional sports teams, I figure the upside is still in tact.I'm looking for guidance on what zip codes I should focus on for SFR and MF either for the BRRRR strategy or turnkey for cashflow. 

I didn't care for Rentometer and stopped using it but as  professional PM myself I use RentRange.com along with my PM software.

The note is usually just one page, but if the collateral is a lien on the property, probably a professional should do that. 

You're marketing the professional service you provide, which pertains to purchase/investment in property.Straight from the FCC:"The term “telephone solicitation” means the initiation of a telephone call or message for the purpose of encouraging the purchase or rental of, or investment in, property, goods, or services"https://transition.fcc.gov/cgb/policy/TCPA-Rules.p...

As such, and given that I'm not from the area, it is critical for my success to establish trustworthy professional relationships with 'locals' that are very familiar with the area.

@Jessica Freese , Lucky you, this actually can be very beneficial for your taxes.1) If you husband makes less than roughly 100k,  the loss from rental can offset 25k of husbands' W-2 Income.2) Even if he makes more than 100k, Since you dont have a W-2 Job, with careful planning, you can qualify for RE professional status, that will help you use the entire loss from rentals against husbands' W-2 Income 3) You can convert some of your personal expenses into business expenses with the home office deductions, transportation expense ( mileage, depreciating computers, furniture, and other assets used for the rentals, and few more. 4) You can hire your kids and funnel money within the house if planned carefully. 

It's professionally managed, so how low can the rents be?

I'm not an agent but I do use a CRM to manage my prospective leads and related professional contacts. 

I’m asking for maybe a rough estimate or maybe a general outlook of possible profits.