Finally building a sump

My tank has been running for about 1 year and it's full of corals, fish, etc..very happy. I'm currently running a Fluval canister filter and an octopus HOB skimmer which just took a dump on me. I think it's time to bite the bullet and make a sump/fuge combo.

I do not want to drill holes in my DT so do I just need to put in a HoB overflow box?? Is the sump as simple as buying a cheap tank, glueing some baffles and putting the expensive hardware inside?? Where do I get the baffles and what kind of adhesive?? How large of a sump do I need for a 70g DT?

 

you have the basic ideas correct. check out this thread for some more background.
http://www.3reef.com/forums/reef-aquarium-articles-how-tos/all-about-sumps-filters-fuges-79852.html