In roughly 9-12 months I intend on purchasing property in Greater Boston area.

Your #1 will bring roughly $885 a month and #2 $1240. 

It would mean more hours and more stress, roughly $15-20k more a year, and a better career path.   

This is a very generic rough answer but if you want $4k profit you need to hit at least ~$8k of rent coming in.

PITI is roughly 1,000/mo even though the rents are 1,400/mo. 

I understand roughly how the capitol gains are calculated and so that is why I am assuming that for our profit.

We got a 5% interest rate and paid roughly 2k in closing costs.

Right now we have roughly $6,000 in debt and together make around $100k a year. 

For example, when flipping a property, I know from experience that it will cost me roughly $15 per square foot doing majority of the work myself and about $28 a square foot if I contract out the work.

I have invested roughly the same amount of money in real estate and the stock market and over the years and thanks to appreciation my real estate investments have overtaken my stock market holdings and REI now makes up about 75% off my net worth vs. 25% in stocks.