I learned the hard way on this topic, and had to deal with bad information that my bank gave me. I bank with Wells Fargo in California. Be aware, that you may get 3 different types of "advice" from your bank.
Cahsiers Checks or "Official Checks" can be stopped and funds held for payment. You can stop it for any reason, just call your bank, however, unless it is lost or stolen, meaning if the Recipient who it is made out of has it, it aint stolen, it will eventually have to be paid once the recipient has his bank file a dispute with your bank. In tht dispute, if the Disputer is the person the Cashiers Check is made out to, then your bank is required to fund that check.
Money Orders- Can be stopped for any reason. They offer the the Seller little recourse and plenty of headaches if they are stopped. The buyers bank can hold funds.
USPS MO- are like cash, and cannot be stopped, and are your best bet if accepting that form of payment. There is a $700 limit, but, that shouldnt stop someone who can afford a $5000 amp, to pay 7 $700, and 1 $100 MO, at a cost of $5.40 (.90cents each MO)
good luck on this Glen