Newbie alert! HELOC vs Refinance? Opinions?

[Shauna Mooney]

First post on the forums...please be gentle! :)

Considering all the options for financing my first ever investment property. One obvious way is to leverage our primary residence. Would love some experienced opinions on how (or if?) to get some equity out of our home: 

Current mortgage balance: $224K (and paying for PMI)
Current 'Zestimate': $271K
Comps: Neighboring house sold for $295K last year, and is already back on the market for $349K, another neighbor is listing for $400K within 30 days. Another possible comp sold for $339K, and there is one pending for $299K. I'm no professional appraiser, but these are all 3 bed/2 bath homes built in the same era (1920s) with incredibly similar square footage and lots (1600ft/.33 acres) and same basic amenities (none of us have garages but we all have recently renovated kitchen/bath) 

Besides the 'hot market' that is happening in our little town, we did also do improvements to the home since purchasing it- including a new roof, gutters, encapsulated crawlspace and landscaping. 

Sooo having said all that; what would y'all do in my situation? Should we refinance and get rid of that PMI and maybe lower our 4.25% rate? Would we be eligible for a cashout refi? Could we get a HELOC and use that for a down payment on another property? Or should we leave our primary well enough alone and keep saving cash/read Brandon's Book on Investing in Real Estate with No (and Low) Money Down for other options? (Side note: I'm gonna read it anyways.)

Just wanted some opinions from seasoned vets and professionals. Thanks!!