First off, if their take home income combined isn't at least 3 times the monthly rent than I wouldn't even bother running their background if the income isn't there.To answer your question I would evaluate each persons income separately, but use their collective income to qualify. 

Also, besides evaluating our Cash Flows, and personal credit, and the potential purchases, what else will I need to execute the deal?

One of the keys when evaluating a property is to have an exit cap greater than an in-place cap rate.

I once stayed in a small log home on the lake.

When it gets large enough to pay one off, evaluate and buy more or pay down. 

I mostly rely on pictures to evaluate the rehab and do my offer.

Evaluate a property quickly for this site. 

I was out for last few weeks and wasn't logging onto BP either.

@Robert Adams - There is an option to sort by "recently active" - which will show you those who have been most recently logged into their account.

I did my own evaluation on the property and found that homes in this neighborhood are selling for around 329-347k.