New to REI, looking at 4 unit townhome row?

[Kelsea Barada]

My husband and I are brand new to real estate investing! We are currently renting and are content with that, but will soon have a one time influx of cash that we are interested in using to get into RE. I've found a 4 unit row of townhouses for $500,000.  They have been on the market for 141 days already, and we won't be ready to buy for another couple months so if they're still for sale then I'd assume we can get the price down.  They're in a less nice part of town but are on the outskirts of 2 areas going through urban renewal. They're walking distance to: a new (successful) brewery, a great new street filled with restaurants and bars, a minor league baseball stadium, and a new 60 mile river bike trail. They're also a 5 minute trolly ride from the main downtown area.  If we bought these we would live in one and try and rent out the other 3. Let me say that we will obviously have an inspector come and look through these, as well as my grandfather (who is in roofing) and my father in law (who is a mechanical engineer that loves wiring houses).    

For the money: we would intend to put down about 15%, and use about $30,000 to update and refresh the units. I've been looking but can't tell if we can use the VA loan for this (with about a 2.5% interest rate) since it isn't a single family home. I don't think that we can, so (from the online calculators) it looks like we can get about 3.6-4.4% interest rate. Am I looking at this correctly? And is $500,000 a completely unreasonable amount to begin with?

And HERE is my MAIN question:

We haven't seen any of the pro forma or actual return numbers on the unit yet, and I'm wondering if they will really (or should really) have an impact on our decision.  Let me explain that in more detail: our idea for these units is not to keep long-term renters.  These units are near a military base (where my husband works) that sees a constant flow of airmen staying 4-9 months at a time.  Their housing allowance ranges from $31/day to $91/day (depending on base vacancies).  We would like to advertise only to them and create relationships with their squadrons that allows us to be full year round with the airmen coming through for various training reasons.  These townhouse units are closer to base than any other apartments in the city, but still walking distance to a lot of the night life and restaurants.  Is our reasoning legitimate or are we using our imagination to create a fairy tale?  We feel that this is an up and coming area, whose property prices will go up as gentrification continues, but is that and our tenant "plan" enough (and thought out enough) to convince us to make a move? Any advice is greatly appreciated, even if it's just that we are fooling ourselves!!