sounds like you got it all figured out man. you know the seios are almost worth the total you are paying for the entire set up, right?? and since you have an overflow you should be good to go. what kind of pump are you thinking about getting?? i run a mag7 on my 55gal and everything seems to be happy with the flow so you may want to consider something equall to a mag9 or maybe even 2 of them.