Next on your list, if you're looking for a little more, without breaking the bank
a Fastman throttle body $212, and a Magnaflow Y pipe $30.
more air in, more air out = more power.
an internal combustion engine is basically an air pump.
Every little mod measured on its own may seem useless to some,
but gradually removing restrictions, no matter how small add up to more free flowing system as a whole.
it only takes 10 tenths to equal a full second quicker than a stock truck, only getting there 1 tenth at a time ? who cares? it's fun!
Now a second my not sound like much, but its over 10 truck lengths on a quarter mile.