If your Alex wheel is still going strong I'd keep it as backup. Most important thing about wheels is to make sure the spokes are evenly and properly tensioned. Fusions or Open Pros will work fine; I'd stay with 36 spokes in 3-cross pattern and use some good hubs like Shimano. Use good quality stainless steel spokes and brass nipples.

Roadies go for these crazy low spoke wheels then gripe and moan when they taco them because one spoke lost some tension. I came up on a big rider in a charity century ride and he was cussing out his wheels because he'd broken a spoke for the umpteenth time. I suggested he ride the broom wagon in because his rear wheel was about to fold but he didn't listen.

He did end up on the wagon because he broke another spoke which tacoed the rim and caused him to crash. Road rash and a busted $1k wheel but at least when he first got the wheels they looked good.