So, what are my options are far as trying to win this case? Do I file a Motion to Strike the affidavit's as hearsay? And will that work?
somethinig like this is my best guess. what county you in? look at your rules of civil procedure dealing with evidence and business records. the affidavit would (probably) still need someone to testify so you can cross examine them.
i'd say without a bill of sale they have nothing.
if it was me, and i had the time i'd file a motion to strike as hearsay, then follow up with a motion for summary judgment for lack of standing. again, no idea where you are located and your rules there as that is somewhat important before filing summary judgment motion. if THEY file a motion first, file a cross motion and attack their standing to sue.
the most important task is to determine what your overall strategy is:
do you want to attack everything they throw at you now?
do you want to wait until trial and then say "aha! they have not proven their case or proven that they have standing!"
both options have their advantages but the point is you need some strategy in your lawsuit