He's a massive Barcelona fan but unless he thinks he has what it takes(he doesn't) to progress to our first team in the future he would be a fool to go to Segunda B. His level will be a mid table team in a strong league or a top team in a second level league.
Anyway he should go to a team that has patience and develops young players in a relatively strong environment(league). I think that someone like Ajax or PSV would be ideal for him. Maybe Lyon, Lille in France. Teams like La Real or Betis in a Liga. If he goes to a team that expects instant results, he's going to have a baaaddd time.
EDIT: Should also say that he is currently a number 10 and as we know that players like these are very hard to build around. He's suited to a 4231 as the player behind the striker with strong workhorses behind him. I feel he'd be lost in a 433.