Perhaps we could do some practice battles over either wifi or PO sometime? I've been trying to find a good pokemon to put in the final slot of my team, but haven't had too much luck, although I think I may be on to something.
Reuniclus is quite good due to the fact that it has magic guard and it's quite bulky. Two sand-summoners is a bit much, so I'd choose one or the other. Golurk and DW gliscor are also quite effective in sandstorm teams. Landorus with choice scarf is a bit like a 2nd excadrill, so not completely necessary. I'd reccomend a level 1 aron with sturdy, endeavor, and a shell bell as a nice, annoying pokemon. Ferrothorn is nice due to its great typing. Any rock types greatly appreciate the 1.5 sp def boost from the sandstorm. Those are the pokemon that I use as part of my sandstorm team as well as some of the ones you mentioned.
I usually train pokemon that either I currently want to put into a team, think might be useful in the future for making a team, or just to make some crazy pokemon with gimmicky movesets. In order from the most used to least used of course :P