Baja Bound is as easy and cheap. If you are going to go for 2 weeks or more just get it for a year, same price. Get your FFM at the boarder when you cross. Peso's from your bank or at Costco San Ysidro, anybody can walk in and exchange, go through the out door.
It's required by Mexico, think of it as a Visa. If you are less than 7 days it is free, you just need a current passport. Go to the Immigration office where you are crossing fill out the paper and they will stamp. You are good to go. Read you Ins. docs. if you are drunk and involved in a accident It is void.