Probably amare but I'm biased, lol. Anyway Amare has actually been pretty lousy the last 2 games after having a nice long stretch of good to great ones. Jonas on the other hand has just come back from his injury in great fashion, becoming a double double machine along with adding blocks. Although I would like to see more games from him to see if he's worth keeping the rest of the year.
All in all I would go with Stat if you need the extra scoring or Jonas if you need rbs and blks. Stat can rb and blk too but not as consistently as Jonas, so far anyway.