The buyer had 10-14 days to inspect the property with a guarantee of 100% refund pursuant to Florida RE law. 

It's an easy to read book by David Rousher about the basics of MHPs.

When you submit your offer, make sure you have a due diligence period that gives you enough time to do these inspections.Once you get the property under contract, have the septic company do their inspection, have an engineer visit if necessary and get your property inspector out to do a full property inspection -- if he is concerned about a major plumbing issue or mold issue, you can get those specialty trades out to take a look and give you an estimate.If it turns out there is a bunch of extra work in these areas (or ANY areas) that you didn't expect, you go back to the seller and basically say, "Hey, there were hidden defects that I needed to bring in specialty contractors to evaluate, and here are the reports they provided. 

Usually go with non refundable down payment,  some type of monthly credit towards their purchase (only if negotiated ), buyer responsible for all repairs ( assuming home is in good condition when they are buying it) and if they are not able to execute at the end of the lease term offer an extension period with possibly a little more down payment. 

As a first time investment buyer, I just don’t know which is the better investment.

Basically “move in ready”.

Set up basic website3.

You have to find lenders (and there are plenty of them in Arizona to choose from) that offer non-recourse loans where the solo 401k account is listed as the buyer (not you as an individual).

The person who can go see the property and meet/greet the seller/buyer.

Welcome to BP @James Russell, As you mentioned above, making sure that you have the basic knowledge before jumping in is important.