I am purchasing a vehicle out of state. How can i secure, or insure i
do not get burnt on the deal. The seller has agreed to our price of
5k, and has emailed me a signed Bill of Sale. It reads the vehicle
year, make, and model with the agreed on price. Terms are 50% down and
50% on delivery via electronic wire transfer, cashiers check, or cash.
It also has the serial number which i did a check on and it is clean.

Credit card will permit you to challenge the charges within 60 days.  
PayPal will make sure the buyer has received the product (and releases
the funds) and the seller gets the money.   Also, through PayPal, your
credit card info is secure.  And if the seller won't agree ... should
make you think.