No matter what you think of Ohka (personally I think that while he won't miraculously become a top-tier pitcher, he'll put up very respectable numbers), that editorial seems a bit slanted. Saying that his durability is in question because he has only gone over seven innings once this season is, with all respect to sportsline, pure nonsense. For one thing, it's wrong: he also went 7 1/3 in April to get his 3rd win. For another, it could also be pointed out that he's gone 7 or more in 8 of the last 9 games. So much for that argument.
Usually, you can expect better from sportsline... (Oh well - everyone misses one now and then. They're still a great source).
The point about Ohka's low k totals is legitimate, but if Montreal is serious about making a run at the playoffs and trading for additional upgrades, the wins should come.
Anyway, I think Fogg, Ohka and Lopez have fairly equal chances to succeed over the rest of the season. That's also the order in which I'd take them, but that's based more on a hunch than anything else. They're all very nice free agent finds.