Is Larry Brown's staff at SMU any better than the coaches in the D-league? Probably not. Plus, half a college coaching staff is hired to recruit, for the D-league all they are hiring are player development coaches.
Brown is a hall of fame coach. He may be a dbag who gets on players too much but I'd bet he's better than every D league coach. Europe is the way to go for this kid, it may keep him off nba radars but he will make more and face better competition.
This season, since the first game was played, only 5 players were brought onto NBA teams from minor leagues around the world, other than the NBDL. From the NBDL, there were 115 call-ups to the dance, per the League's transaction records: Some players were called up multiple times - but doing a manual count, I came up with 56 individual players going up from the D-League to the Dance. At the end of the 2001 season, there were 103 former NBDL players on the final day rosters. (Sorry, don't havea the total for this eason yet).
http://www.nba.com/dleague/dleague/transactions.html
The money is better overseas, but I sincerely doubt the talent level they'll face is nearly as good on a consistent basis - and the coaching not even close. (Go to this link for a list of the NBDL Coaches who've ALSO gotten the call up to the NBA:
http://www.nba.com/dleague/news/coaching_callups.html
If they're doing this for the quick bucks, Go overseas. If they're doing it to get to the NBA, go to the D-League. The overseas money will still be there if you find you're NOT NBA-Level. They're paying top dollar overseas for guys with good D-League success.