Rafael,
Just use a regular purchase contract with a contingence clause that says you have to find another buyer before you will exercise your option – you’ll also need to put a timeframe on it – 30 days – 3 months, when you can make a 10% profit, etc.
If your buyer is getting financing, you’lll run in to a problem with seasoning if you are the seller. So, it may be necessary for you to get paid to terminate your option so the seller can sell directly to your buyer.
If your buyer is getting financing through a hard money lender or private lender, seasoning is usually not an issue.
Ideally, you’ll structure your contract with seller financing so you can pass that on to your buyer in the form of a wrap.
To sell your option – you are actually selling your contract. You can either use an assignment of contract or do a simultaneous close.
Jackie