I was able to find a few good subs like electrical, landscaping, roofing, AC tech, foundation, yet can't find a good general contractor. 

Roof, windows, landscaping, carpets, paint job.  

, roofer to see if they are getting into the exhaust vent on the roof?

The last think you want to do is to put leverage on one of them and then need a new roof or furnace.

Its easy and cheap to insulate accessible locations like an attic and since heat rises and the sun beats down on your roof the attic insulation is probably your best bang for the buck when insulating.

Also remember it will take time to get them done, during which the home is vacant and not on the market.People shop with their eyes-so many don't care about stuff that is really important (plumbing, electrical, roof, etc). 

Whether you are purchasing your first home or the next real estate deal, closings can be a nerve racking process.

I like nicer houses that just need paint and flooring or maybe a roof.

Building Details:- 2 on bottom 2 on top - 3/1.5 ba 1100sqft - 7 yr roof - prob $35k - 50k total work/updates to make awesome.- Neighborhood ~ C- but a C- area here doesn't mean too much, smallish town ~ only about 50k peoplePurchase Price: $660,000Appraised Value at Purchase: $730,000Interest Rate: 6.625% - 30 year fixedDown Payment: 10% / $66,000Cost to Make Rent Ready: $14,000P&I - $3803 T&I - $898Total PITI - $4701/moCapEx, Vacancy, Maintenance - $1099/moTotal Monthly Costs - $5800/moCurrent Rents - $3800 (3 units)Fair Rents ~ $5000 but will likely only charge ~ $4500 to start.

Large projects such as roofs, repipes, or HVAC only get about 50% - 75% of the actual cost.