Fan configuration for external w/c box

Hey everyone, I have a few questions about the fan setup on my external w/c box. First off heres a link to my box http://www.techcool.com/vpc/water/tcwater/4000x2sideintake.jpg

or rather what I built mine based on, mine is "exactly" the same however, I'm using only one single 87 chevette heatercore on one side of the box, the other side I have just solid wood instead of setup for dual rads/cores... so the two fans which are 120mm btw should they pull in air, or exhaust? and on the solid side, do you think I should add a fan here (intake or exhaust) and lastly the heatercore...I have one shroud, should it be mounted on the inside or outside of the box, and in what fan configuration? because I can adjust the side to either accept the heatercore flush (shroud inside or outside box), or the shroud flush ( turned either towards the inside or outside...If you need any clarification just ask

Also, while your looking Mag3 pump..wheres the cheapest place for these right now? So many sites I can't keep up.

Thanks for the help guys..feel free to draft up a pic in paint or something if you have a better idea..

http://www.techcool.com/vpc/water/tcwater/4000x2inside.jpg

additional pic of how they have theirs setup...

Anyone?

welcome to the form but that set up needs some more room but to answer your question i would go and have them suck in that way you are not heating you system back up a little