Unfortunately, there is no one size fits all approach.

From my understanding, the IDR plan will factor in my income and family size, making it more affordable. 

Could be your housekeeper.I've found that condos that employ an on-site agent who lives at the complex typically have higher dues because it is not cost effective to do so.

LTR, MTR and STR work in most larger markets (~top 30-40 cities by pop, or be proximity to metros/attractions/employers).

Assuming the ditch is a foot wide that's almost 14 yards of dirt, which is a full size dump truck worth of material. 

Lubbock just has healthcare & education as major employers.

I’m not trying to rain on anything here but the reality is that measuring Btus delivered to individual units via airflow is by its very nature imprecise - if you want to know why, read on...The size and length of the ductwork is but one factor ( of many) that will yield energy losses while that warm air is being moved to your units.

As far as the size I think it would depend on the space. 

With the funds you listed and property size you should be able to comfortably have 2 even 3 projects going at once (depending on what you're up for), especially after you sell the current house you are renovating.

@Andrew Caton What size deal are you looking for right now?