First off a well established larger builder will not require a down payment for any part of the build. The builder who is well established will only ask for payment on delivery and acceptance. The builder may offer a discount for payment of the chassis and in doing so a performance bond would make sense.
If builder is ABLE to provide a performance bond likely is sufficient info. Do you want to spend (waste) the $ on actually buying the bond? You sniff around very much you'll find out what dealer or mfg are in trouble. If they on cash terms with major suppliers that tells you ALL you need to know. If the have to pay Akron with ccard to order valves it's not looking so good.