So would I.

I would also accept a deal in which one of us at random is killed, and the other one gets the machine. And I don't think it should make much of a difference whether the coin deciding who gets killed is flipped before or after Omega offers the choice, so I don't feel too bad about choosing to kill Frank (just as I wouldn't feel too outraged if Frank decided to kill me).

I would also find way more interesting things to do with the machine than seat cushions and the Mona Lisa - create worlds, robots, interesting machines, breed interesting plants, sculpt, paint ...