New boy needs your advice

Hi, I am the new boy on the forum. In the past I have had very good results with my lawn tractor 1 wheel horse 2 craftsman's and then a Toro.
All of my engines have lived to be old . My decks have not faired as well I have a solution for that. My question to you forum members is would you rather have a one cyl Kolar or a two cyl Briggs. I have narrowed down my search to the Husqvarna 42: with a 19 hp kolar or one with a slightly larger 2 cyl Briggs. I like the idea of a twin so it do not have to work so hard. Any ideas? Also since i am soliciting your opinions . What about a transmission? Do you like the standard or one of the auto types for long term longevity? I would like to hear your opinions.Thanks Jim