I have 1 MTR I just rehabbed bringing the value to 160k which is my needed DP for the STR on the beach.

I'm looking to purchase a condo/townhome in Houston that I intend to use for STR on AirBnb.

Some areas are owner-occupant STR only. 

The Masters hold a tourney out here every few years for example, and having it up for STR on that weekend alone would be worth the hassle. 

Personally, if it's quick, I would recommend keeping the current STR on the loan it has instead of refinancing it to pull cash quickly.Run the math but I think it would be much better to do 10-15% down (or 20% if you can save up quick enough) on the new primary. 

If an investor wants an STR on Maui they are limited to investing in condos. 

Purchase price: $665,000 STR on Lake Charlevoix. 250 ft of water frontage and 4 miles from Boyne City.

Purchase price: $260,000 Cash invested: $45,000 STR on Lake Thompson in Rhinelander, WI

Being that I sell vacation rentals here in Orlando and see how much goes into management, I think it's a huge project to do STR on a mobile home park but if you have a way of getting the marketing dialed in and someone to oversee the park I'm sure it will work out.

Since you mentioned arbitrage, I am assuming that your plan is to lease the property from the owner and then rent out per night as an STR on airBNB.