Section 8 can give higher rental revenue but there are a few things to keep in mind. 1.

Where people went cheap with online brokers, many of those companies just did not have the resources or expertise is seemed in many instances to handle claims. 

$500,000 after taxes is likely close to $325,000(maybe more or maybe less).Assuming cash-flow from rentals is offset by depreciation, you would need $325,000 of annual cash-flow from the rentals.If you can get $200 / door / monthYou would need 135 doorsYou can work on this type of math to figure out how much rentals you need.Be mindful that rentals require some type of work.

Land Investing Online.

Jackie has a good point that much of it is free on line.

From what I can tell online, the RF1 zoning district is designed primarily for single family row houses (like townhomes).

Check out other online guides available here: https://www.biggerpockets.com/guides3.

Keep in mind, though, that this approach comes with higher down payment requirements and interest rates, which may not be as favorable

Personally I have not had much luck with seller financing when there are agents involved - most don’t understand it and think it just makes the deal more complicated.Did you check with your bank to see if they will mind you having a second loan on the property?

Here is a calendy link if you wanted to chat on a zoom or call. https://calendly.com/trepador64/online-meeting