I'd like to approach them immediately, and see if they would like to buy back the house on a land contract, however I can not find any info if this is allowable during the redemption period.Does anyone have any successful strategies for obtaining possession earlier than 6 months? 

Even if they can't afford to stay at the home, we can frequently regain possession quickly and in great condition, allowing us to turn the unit quickly and keep the home performing with as little expense as possible.

In the conditions of the sale of the house THEY could've put that they were not going to take possession until their lease was up.

I am in the process of purchasing a SFH that has tenets in place (for years), but not in possession of a contract and have not paid their former landlord for a long time.I was going to speak to them and even pay them to leave if necessary (cash for keys).  

I was found guilty of misdameanor possession of marijuana in Pennsylvania in 2012.

Your first case is for possession, and the second case is for a money judgement.  

If you find yourself in the latter situation, then you can decide if it's something that would make it difficult to sell.Right of redemption varies state to state and is relevant to foreclosure auction sales (ie. court has not confirmed title transfer and sale), not REO where the lender is in titled possession. 

You then must post a "3 day notice" to pay or give possession.

We can't take possession of it immediately so we even asked him "can you wait till September for a cash deal?".

You have possession and ownership of the property for now, but the first can foreclose and you will lose it.