Question: Pre-drilled tank? Cannister filter? Trying to upgrade my set up!

I'm trying to upgrade from a 20 gal to a 75 gal, and the one I'm looking at is pre-drilled. From my understanding, the tank water drops into an "overflow" which is just another, smaller tank underneath & a pump empties the overflow into the tank in a continuous cycle.
How exactly does it work though, and is an external cannister filter compatible with it?

Another question I have is if cannister filter includes its own pump & if so, can I use it to pump water through a chiller or should I use a separate pump? I have my eye on the Marineland C-360 if that helps, and I have a 1/10 HP Aqua Euro chiller.

Also if anyone knows of any low intensity lights that will support plant growth that I can use, that would be helpful.

It looks to me like that Marineland canister filter comes with a pump, though I can't seem to find information that says one way or another. I think that it must because it states the max flow rate and people say that it is a quiet filter. I don't see any reason this couldn't work with an overflow or with a chiller inline, though you may experience a drop in flow rate with the chiller unless you add another pump between the filter and chiller.

You may want to move to a slightly larger filter since it is for up to a 100 gallon and with a 75 gallon, an overflow, and about 2.5 gallons of water in the filter (per the manufacturer), you'll be approaching the upper limit of the filter's capabilities, especially with those wonderfully messy animals in there.

I personally use two fluorescent GE Plant and Aquarium F15 bulbs with my 55 gallon and give my axies a lot of places to hang out out of the light, and my Java Ferns grow like freaking weeds. My girls tend to hide under their large overhang, but are constantly exploring their tank.

Hm. I didn't even consider the fact that an overflow & canister filter would increase the total gallons in the set up. I may want to go with a 55 gallon instead so my chiller will have some wiggle room during the hot summers here.
Thanks for the great info! I'll look into those lights.

Can a canister filter be used without an overflow?

I think they can be used that way, yes. If I were doing it with a predrilled tank, I might try using the holes to run the hoses for the canister