wow - going to be a tight fit. i'd go to target or wal-mart or something and see if you can find a food grade plastic container to use as a sump. you may also be able to find a 15gallon High tank or something to fit in that space.
i'd go for the shortest distance of the tubes that you can. you don't want piping going across your bedroom and plus you need gravity to work in your favor on the overflow aspect of it.
Actually, you could empty the water temporarily into a container if you were going to get a taller stand or change stands. Hmmm....I agree with MattSeattle in regards to finding a food grade plastic container to serve as your sump if you are unable to find a tank to suit your space.
also don't forget you need an overflow for your tank as well as a return pump. also you need to calculate how much water is going to drain out of your tank when you turn off the pump or a power outage. your sump needs to be able to hold that water plus the normal amount of water. my 55 gallon drains about 3 gallons of water out when i shut off the main pump...maybe a little more because i've never calculated it to an exact measurement. total my sump holds about 20 gallons of water.
I think a garbage can might work on the left side of the tank. U might be able to find a Large Tall Kitchen Garbage can, that would probly work the best from what I can tell.
I guess I am curious why you are trying so hard to fit a sump somewhere. Do you not have enough room for all the necessary equipment or just looking for additional water volume?
I ask because contrary to popular belief you can have a sucessful tank without a sump. I have had mine running for almost 3 years without a sump. Are there drawbacks...Yes. But I don't know that forcing a configuration that is less than optimal is a better solution for you. Just a thought.