James,
Perhaps it would be helpful to explain your exit strategy in more detail. 14 to 18 months is a long time to hold REO unless you are generating income (rentals). Time is generally not on your side to maximize your ROI - taxes, utilities and maintenance add up quickly.
Also, what price point (discount) are you buying them (at current market value - not BPO)? What ROI are you looking for? What is the general condition of the properties? Deteriorating properties over time and risk of vandalism also reduce ROI.
173 properties is pretty big for what sounds like a 1st endeavor - without a full plan - and backup plan fully in place and proven. Also, one package of that size, in one geographical area puts "all your eggs in one basket" - food for thought.
Have you thouroughly vetted the seller? I have not seen that large a package in one area of FL (assumption as that is your location). Frankly the only geographic specific packages of that size I've seen have been condo's and builder buyouts. Are they in FL or somewhere else - what metro area? I'm asking to determine the local market trend and risk.
More info might help us help, you as we seem to be going in circles here.
Greg