There are alternatives to PayPal, however you have to also take into consideration your customers requirements. Most have no issues trusting PayPal's gateway, so you can risk sales by not offering what most consider to be the industry standard. The other point I would make is that it's only an initial hold, once cleared, funds flow without regular holds.
What you can also do is get on the front foot and contact PayPal to asj them what account information they would like to assist in verifying your account as quickly as possible. You can also ask your customers to inform PayPal of the successful delivery when they receive it, this will see PayPal then release the funds.
So yes, holds car be a pain, but you can quite often minimize the drama with a little forward planning.