TheInuk20: antyway of concentrating bonuses on them that I missed or just totally random chance? Even with sponsor chosen as SE
By selecting SE as your sponsor, as you probably already know, guarantees you at least one SE item in each box.
To increase your chances of an epic, or rare, item, you could play higher level coin rooms. Higher level rooms provide more opportunities for epic and rare items.
You could also, if you want to spend credits, purchase the gold or platinum gift boxes in the Pro-Shop, which such boxes are more likely to have epic and rare items.
I have been told by WGT that the items in the boxes are totally random, despite the fact that the silver boxes I receive in the showdowns seem to always have the same item and the more I need an item, the less often I receive any of the kind.
Last, you can wait to see if WGT has an X-Mas/holiday give-a-away and ask for the items you want.