I have bought and sold horses on payments several
times. The way we have done it, is to write out the checks for all of the
payments. Make the seller promise not to cash them until the date on the check.
Buyers make sure the money is in the account on time. Has worked for us so far.
No hard feelings between friends that way. Also, papers aren't exchanged until
last check clears. Horse goes to new home right off, with understanding that
deal is done, no matter what happens.