As someone that has owned Soriano for years in a keeper league, I know the highs and lows of owning Alfonso Soriano. There are times when it's bliss, but times like right now Soriano when he's slumping are terrible.
He gets tons of points in the catgs you mention, but they come in spurts.
Given that he's at a low right now, you might be giving up too much to get him. I agree your OF would be upgraded, but I'd only give up one of those guys. Is the other guy desparate for pitching? He might be feeling like me that Alfonso is all he can shop right now. I'd go for one or the other for Soriano.
OR, I'd offer him Jurjjens + Maine ... a weaker 2-for-1.
Good luck. Help with mine?