I looked at big singles versus twins for the same reasons, and since I live
on Lake Michigan and travel east quite a bit, I chose a twin. The redundancy
goes beyond just the engines, and includes dual vacuum pumps as well as
electrical systems.

Of course, this also means that there is double the maintenance on these
items, and double the chance of something breaking. You should not buy any
airplane unless you can also afford to maintain it- patching stuff with wire
and duct tape is the first step toward having a catastrophic chain of events
occur at an inopportune time.

I did most of my training in an Aztec, and then flew a Baron. The Aztec has
bigger engines, but is slower. It did not have the solid feeling of a Beech
product, but parts are a lot less expensive. Finally decided on a B-55
Baron, and it is heavily equipped with known ice, radar, stormscope, etc. It
gives a lot of flexibility, and still has a full tank useful load of 760
pounds, with a cruise of 175 knots. The IO-470 engines are solid, but fuel
burn is around 25 gph. Even a short trip for lunch comes with a gas bill of
around $300.

Again, the most important issue is to never scrimp on maintenance- these are
complicated airplanes, and trying to save money by postponing repairs is
short sighted.