put a lid on it to keep moisture in. you can also put the sump alongside the tank, or behind it, even above it.
as far as turn-over, it depends, for particulate filtration it's generally said to run 5x-10x your tank size per hour. for biological filtration 2x-4x per hour so the water is in contact with the bacteria longer.
do some searching and you'll find many opinions on it.
my sump will be mainly biological and I'll be running about 3x an hour for a 245G.
you can use pretty much anything for a sump, many people use rubbermaid tubs. you might even be able to post a trade on-I was going to say craigslist, but your canadian so...kijiji?- your 40 for something that would fit.