My grandpa used to call Longhorns cow-fresheners...not in a good way! AJ, I'd also have to disagree with you on assuming anything but a Longhorn or a Red Angus will cause a visit from the vet. From experience...Our first calf heifers (Shorthorns, Polled Herefords, and crosses of the two breeds) are bred exclusively to a Maine and Shorthorn bull. The calves average about 80 pounds, are born unassisted and are up in 20 minutes chasing the heifer around for breakfast (I'm not sure if this fits your definition of calving ease though). Not every Shorthorn or Maine bull will have this result...but neither will every Red Angus.
I do like the suggestion of Fischer's Gus bull. Our calving ease herd bull is a relative through the Mr Gus line. You will probably get an okay birthweight (85 lbs), and the calves will be fairly moderate in bone size. (as opposed to the larger bone wanted for the show ring). The calves likely won't be very clubby either, but he may add a little more flank and a touch more broodiness to your heifer. It could turn out quite nicely IMHO.
I haven't heard much on 844, but he's supposedly also recommended for heifers. The pedigrees on both bulls could leave you a good cow if the calf comes out a female.