All three are possible. Beldum definately won't be too bad.
I'm going to assume you want Magnet Pull on Magenmite, because OHKO moves are banned (unless this is for Battle Tower?). Probably will come as modest considering my ditto collection, but I'm a little confused on this IV spread. You want a Magnemite with a 31 in attack? Why? By the way, I read spreads as standard HP/Atk/Def/SpA/Spec.D/ Speed. Perhaps there's a misunderstanding. I won't start this one until I get some clarification.
Rhyhorn doesn't have solid rock until it evolves, and it MUST have rock head as a Rhyhorn in order to evolve into a Rhyperior with Solid Rock, so don't be shocked if if doesn't have Solid Rock. Spread is doable, and you probably will be getting and adamant one.
By the way, what do you have to offer? I'll get started when I can (probably tonight).