if you can ride up said hill yourself at say 4mph, you'll be able to ride up it two to three times as fast on a vado SL or creo SL. your power + 1.8 * your power = 2.8x your power.
looking around omaha and reading some online references to the hills, i don't see anything insanely steep (then again i live in san francisco so we may have a different frame of reference!). if you're going up at 4-5mph i'll hazard a guess that we're talking about a 6-8% slope max unless you're a very strong rider. go over to bike calculator
http://bikecalculator.com/ and enter what you think the stats are, and switch between say 150w, which gets you up a 7% slope at 4.5mph, and 330w, which is what your effort plus a creo/vado would equal if you were contributing 120 watts (20% less than 150)... you'll be going 9.5mph. if your power drops to 100w, the motor power would drop to 180w, but you're still at 280w.... going over 8mph and doing a lot less work.
the SL bikes start to get iffy with grades in the 15-20% range, where the motor output is maxed out, and the total power of rider+motor is only enough to go 5mph or less. there are often unpaved roads this steep, but paved roads in the united states are really, really rarely that steep. the SL bikes sound like a great choice for you, and the beauty of them is that they're light enough to not make your own contribution less significant, and still a ton of fun to ride.
if you decide you want drop bars, the new versions of the EVO creos (expert and above) have 11-50 rear cassettes, stock 44t chainring but you can go a bit smaller. with that kind of gearing on a vado or creo plus the motor... i bet you can ride up anything paved in omaha.