I personally like the 10 gal setup. However, you're gonna do just fine with your 5 gal as long as you dont brew REALLY BIG beers. I use a gravity feed (just a piece of hose) to get my hot water from my HLT to my MLT. Some use a pump. You can do some searching on the forum to learn more about that. I cant do it in my apartment because of space issues. You should start looking at the "3 tier setup". By searching for this you'll find that people have ingenious ways of moving water around and dealing with your very problem.