I would factor that HELOC 'cost' into the multi purchase when you do identify it but multi rates even without owner occupied right now are around 3.25-3.5% so it's very attractive for a buy and hold strategy. 

Given my current cash situation and the high value of homes in the Denver MSA, I'm having trouble identifying which method would work best for me.

I could go out right now and come up with dozens of properties that I'm interested in, and you really do need to identify a LOT of properties. 

We want more than the standard 45 days to identify a good property to move our equity into via the 1031 exchange.

@Logan Pettigrew some MLS systems have a field to identify them outside of the description.

Purchase price: $700,000 Identified and acquired a low-risk bank owned duplex in San Clemente for a long-term hold period.

Purchase price: $700,000 Identified and acquired a low-risk bank owned duplex in San Clemente as a long-term hold.

-Identify the highest-and-best-use given the current improvements, economic environment, tenant demand, and cash on hand.

The most important thing is identifying your goal.

Worst case scenario you sell it, best case you refinance and keep itAfter living in 2nd house hack for a year or so, repeat this process.During that time identify a few possible BRRRR properties.Rinse and repeat.This is nice and tidy and may not be how it plays out in reality, but in essence this approach gives you a few things of value:  repetition and equity.