Well, on which has the better upside, Schremp and Radulov. But on who I think will have scored more points in the NHL in 3-4 years...
I think Tukonen and Picard, because they are likely going to get a chance to play. Tukonen has been touted as very NHL ready, and I think Picard just because I have a feeling he'll play in the NHL sooner rather than later.
Although I think Schremp and Radulov do have higher ceilings, I can't see either making the NHL until they get an opportunity to play in a scoring role, and I don't really see that for either in the next couple of years. Maybe a few years from now, but I doubt either puts up as many points in 1 year as Tukonen will get a chance to put up in 3.