So basically, the largest markets are out. 

Inexperienced or conservative investors do not grasp the concept that every property has two distinctly different income streams.

As a buyer, what is the largest "repair credit" or cash at closing from the seller you have seen be approved for a FHFA loan?

The other half are 3 or 4 bedroom, my largest has 9 beds and 4 baths in 3 stories. 

The other is Case Shiller index top 20 largest metros (home appreciation) for past 30 years of historical actuals.Notice anything?

Or see where your target city ranks.TerryTop 100 Largest U.S.

It is one of the largest and highest priced homes in Northfield, so the buying pool is pretty limited. 

Are there any distinct advantages to one or is it more based on my credit score, debt to income ratio and down payment as to which may be more advantageous at the time of purchase?

I work for Redi Carpet (largest multi-family flooring company in US) and I can get materials and labor almost at cost. 

Loopnet for example is owned by CoStar, the largest commercial MLS in the US and most widely used by brokers; no matter the market CoStar generally will have the most complete set of listings.