You wouldn't be contingent on selling it which is a big plus. 

I've found a few online though I'm looking for one that has-property description, condition, purchase price, closing date, default clauses, insurance contingency, risk and loss damage, adjustmentsDo I need all of this and if so where should I get it?

You need to make any offers contingent on a sworn rent roll and a general contractor’s estimate of repairs and upgrades.

The seller has agreed to put the sell of the property contingent on rezoning.

They just might not be licensed, might not be ethical, usually don’t answer to a broker or a regulatory body (unless they are licensed) and use a different sales process where the EM typically goes hard earlier in the transaction and the buyer is on their own with fewer contingencies and less time to do their due diligence.

When the contract says the assignee is paying cash, from my experience, it waives any contingencies that come with a financed offer.

A real estate attorney can assist with drafting a partnership agreement that outlines the rights and responsibilities of each party and addresses any potential contingencies.

This could be contingent on the market you are in so you may want to source locals in your area and how they handle.  

They can often spot potential issues that might not be obvious but could impact your renovation budget.Contingency Budget: Always add a contingency buffer to your budget.

Also, any sort of inspections, appraisals, and paperwork fees are not going to be refunded to you.My advice is to read thoroughly through your contract and take notes of the contingencies and see if there are any specifics in which you can leverage yourself out of the contract, legally of course.