I think bilge pumps have at least as much head as most aquarium pumps. The bilge pump that I have running my auto top off is rated for 550 gph, and it pumps water about 6 feet vertically to my tank. I fill my ATO reservoir directly from my sink faucet via a 10 foot hose, and the bilge pump can pump the water into my tank faster than my sink faucet can fill up the reservoir.
I prefer the bilge pumps because I think the impellers are tougher (made for nasty bilge water!) and because with a system that has to activate pumps via relays, I preferred 12V over 120V for safety reasons.
Petco sells pretty good 120v pumps which have 1/2" threads on the input and output which makes them easy to use, and they're like $12 for the smaller one(200 gph?), and $20 for the larger one (300gph?). I have a few of each that I've used over the years with good success. They're not super powerful, the smaller one can barely pump 6 feet of head, but the larger one has a decent flow at 6 feet of head, not as much as my bilge pump but not far off.
Here's a good $20 bilge pump with integrated float switch:
Petco pumps: (looks like they're on sale online)
I never considered the possibility of corrosion buildup on the float switch that PhysicsDude referred to. It was a cheap part, so that could be a concern. It's been going strong for about a year+, though, and it always sits in an inch or so of water. No problems thus far, but maybe I should inspect it to make sure all is well.
With an inch or so of water I don't think you'll have any issues. Mine is in a auto top off reservoir, where its constantly submerged in water. It still works after 3 years, but I can tell the inside of the float switch has water in it and isn't as sensitive as it used to be, but I haven't had any issues yet. I keep telling myself I should replace it, but have just been too lazy to do so.