HELOC or Mortgage?

Hi,

I have a question I was hoping someone could help me out with.

I'm looking to buy a townhouse to rent out as an investment property but I am not sure what the best way to finance it. I do not have enough savings for a down payment so these are the options I think I have:

I have about $50,000 remaining on the mortgage of my primary residence which would be estimated to be worth around $380,000. I want to buy something that costs up to $300,000 (which would require a $60,000 down payment).

1. Refinance primary residence for the amount of the down payment ($60,000)+ the balance on current mortgage ($50,000 = $110,000. Then get a mortgage on the rental property for the remaining amount of ($240,000)

2. Refinance primary residence to the max (80% of assessed value (80% of $380,000 = $304,000) - amount remaining on mortgage ($50,000) = $254,000) and put in $46,000 from my savings?

3. Obtain a HELOC for the down payment of $60,000 and get a mortgage on the rental property of ($240,000) and use my savings to pay off my primary residence mortgage. (Not 100% sure that this is possible)

4. Obtain a HELOC for half of the down payment ($30,000) and take out remaining half ($30,000) from my savings and get a mortgage on the rental property of ($240,000) and pay off some of my primary residence mortgage.

One of my unknowns is the interest I pay on the mortgage in the first two scenarios tax deductible? Is it worth it to incur more debt so that I may deduct more interest off my income tax?

Thank you for your help.