http://store.gaugemagazine.com/5-gallon-chrome-6-port-aluminum-air-tank.aspx
this is the tank i got it is chromed aluminum tank. tho the chrome not holding up that great. i got plenty of scratches on it. but id still go with this tank again because it had the larger ports on it. most tanks i see dont have 1/2inch ports at all. this one has 2 1/2inch ports and 4 1/4inch ports. id like to get another tank eventually when i switch to a EDC pump! ill probably just sand the chrome and paint it to match the truck when i get the second tank. as to the exhaust why not keep it out the back?
with some planning and custom work its still posible! ive seen it done several ways. depends how low that sucker will go of course. i asume ya wanna drag the bumper so it will have to be tucked up still. easiest way ive seen them done BUT it was thru a rollpan cutout holes but they just chopped out the truck bed alittle more to run the pipes and ive seen it done both ways... either lazy and open pipes in the bed and ive also seen the pipes covered with something like a driveshaft tunnel but for exhaust. ya just want to keep enough room for clearance so it doesnt burn the paint or rub anything.
as to the cutout tips.... just build your own! those expensive ones are all in one i think so they have extra space for heat to keep from burning paint. but hell you dont need it in 1 piece. you just need to cut a hole and simply weld some braces to the pipes to line them up with the hole opening which can be done easily by any exhaust shop. simple steel rod bent to shape it needs and welded to the pipes with a bracket on the frame. and to trim it out try to find a steel shop in your area and hopefully find one that has a nice plasma cutter or water jet to cut out a piece of stainless steel or billet of your choice to a nice shape and either just drill holes and use stainless bolts OR weld on some bolts to the backside for hidden bolts and bolt it to the part your cuting thru. of course the bolts need to be counter set welded on for it to sit flush. but its very doable. just depends how much you wanna spend and how much work you wanna do yourself.
being lazy is always cheaper and easier and lets face it ITS VERY TEMPTING.LOL just keep thinking how you MIGHT BE ABLE TO DO IT! being bagged does have more obstacles you have to try and plan around!
sometimes ya just gotta be lazy right now and plan for later mods. its nothing to be ashamed of.