All the rules regarding tax sale can vary tremendously by state and even local jurisdiction.

VA caps vary from city to city.

I know it will vary by location and by each investor but what numbers do you like to see when analyzing a deal?

I would imagine that the details of how builders structure partnerships vary based on the specific nature of the deal and the parties involved (how extensive is each person's track record, how much money will the investor be expected to invest, how much money are you willing and able to invest to show "skin in the game", etc.). 

Something else to consider if relying on HELOC.

I have spare time quite often, but it always varies week to week based on the weather and seasonal business patterns. 

(Your mileage may vary.) 

Each state has varying real estate laws and practices. 

Didn't have much luck with that, since the target market for this zip code doesn't rely on zillow to find apartments.

While the asset managers will vary based on your region, in Connecticut the current asset manager that services the HUD's is BLB Resources, the place that is always referred to a gateway to bid and find more info is hudhomestore.com.As previous posters have mentioned, make sure the agent you are working with has a valid NAID issued through HUD because they will need one to place a bid for you.