Every system you try will have flaws, or you may salivate over a feature that appears in other software.Some familiar names are mentioned frequently: Stessa, Apartments.com, RentRedi, TenantCloud, Innago, RentManager, Avail, Rentec Direct, Doorloop, etc.I recommend conducting thorough research on each app online to understand their offerings, pricing, etc.

I understand cash offers give you an advantage in any market - but is there any specific reason it's more difficult buying out of state without being a cash buyer?

I want to offer her $350,000 for the condo (its a fair price for it), 5% down payment ($17,500) and pay her monthly $2,000 for 3 years, after which I would refinance and pay her out.

IF the property is different - then maybe the program  being offered is the only one thats  avaiable 

Generally the listing realtor won't show your offer favourably with a vtb.I personally found the best owner financing comes from motivated vendors, in the private market. 

If you already manage your 4 properties, you can build on those systems you already have in place and offer your services to other landlords and investors.

A pure soul might even offer them a market loan product in second position personally. - Let them list the property and make an offer in the context of the market. 

I’m not offering legal advice so do your diligence. 

FOLLOW THE K.I.S.S method plan (keep it simple and stupid).Find and hire a real estate agent that understands multiple investment strategiesGet pre-approved - see what options you havebased on your pre approved price - identify an area you want to invest in that you can affordLeverage the agent to : bring you properties, assist in pulling comparables (you should know your comparables of the area you are looking in, this is for a second opinion) review and confirm your estimated rental income, assist you with acquiring the property, and have a list of resources you could use; contractors etc.Looks at properties and make offers that work for YOU.Also,Do not pull your IRA money out, leave it there and let it grow - leverage this to meet your lenders reserve requirements.Buy Multi family to holdBuy single family to fix and flip and produce more income to buy more multi families.

I worked for Zillow Offers.