Howdy!
I am 73, and since '92 I have owned 2 Craftman's, a Cub, a lesser JD, a Husq YT42DXLS and now a JD X-370 - all 42 in. decks (I can't get anything larger in my basement but wouldn't want a larger deck even if I could)! For me, the absolute worst lawn tractor I ever owned (for like a minute

) was the Cub. I bought it new from a dealer, and the very first time I mowed with it the left front tire fell off, the gas cap leaked to the point it was dangerous and eventually the tank wound up being replaced. It was loud and, worst of all, used way more oil than acceptable. I don't remember the engine, HP or the model #, but it was a POS . . . Finally, it reeked of cheapness all around. Perhaps I just got hold of a bad one, but no second chances for CC.
If I had your lawn - which sounds rather flat to rolling, with few or no rocks, trees, etc., and only an acre, I likely would go with the 42 in. deck. You may find that a huge deck is not nearly as maneuverable and will not follow as closely the undulations of the lawn. Additionally, you may get into a 3-blade situation - more difficult and costly blade maintenance.
I mow 1/2 acre of rolling chain link fenced yard with an outbuilding, a few large rocks and some basketball sized, and an open, one-acre field which is at best rough, and which also is about 1/3 hillside - so steep that a locking differential was necessary until that Husqvarna I mentioned kept trashing trannys. I got rid of it and paid over 6K for the best tractor I've ever owned - a JD X-370. Maneuverability is everything to me. 42 in. deck, hydraulic power steering and deck lift and 2 JD 45lb. weights to conquer those hills - which are FAR too steep for a zero turn! It's a horse! You don't need weights, but the power steering is effing WONDERFUL. It's almost like a zero turn in that respect. Check one out at a dealer and give it a spin!
One other thing whatever you get: armrests are a bonus, but the bumper I bought is now hanging on my basement wall. All it does is keep you 6-8 in. from maximum cutting coverage. Happy shopping!