If you just have one rental you can probably get by with generic tax filing software.

We also had a transient tax and municipality as well.

I've created a free interactive map for the upcoming Philadelphia tax sales auction, where you can easily see the location of each property along with its auction ID.

Right...1st I would say the tax sale wiped out any liens. 

What are the tax ramifications of deducting interest on the two units we rent out on a first lien HELOC if we are parking paychecks and using that line of credit for personal expenses (groceries, gas, maintenance items, vacations, etc.)?

If your friends have a rental they should hire a tax professional. 

I am looking for a firm that has experience appealing property taxes for residential homes in Detroit, Michigan.

Contributions to SEP IRAs can be done after you file your taxes.

There comes a point where having a real estate-savvy tax preparer outweighs your time learning a new software. 

So often rentals don't have taxable income; and once they do it's still not subject to the payroll taxes paid by W2 wages or on self employed income.