You do not want to go over what you need by a whole lot. You will want a circuit breaker next to the battery and one under the hood before it goes into the firewall. You should also have a fuse block between the amp and battery. go with a 100A for the amp, and you might want to go 150A for the other 2. This will give you plenty for the starter to crank. Also upgrade the grounds up front to the chasis and to the block as well. this will make sure that the draw is as little as possible. you probably want 1/0 to run back so that there are no heating issues. Use gromits when going through metal and use split loom when in the engine compartment for protection. Solder and heat shrink all conections. Use a butane torch to heat up the bigger ring terminals and feed lots of solder. This will garentee a long lasting reliable install that can handle plenty of current. Grind all of the paint off of the ground conections as well and go directly to thick chasis metal. Make the grounds as short as posible too.