Depends on who you are. In the long run i do go for Bajcetic but he will cost you a fortune. Seiwald is much cheaper and better at the start of the game.
Btw who needs Bellingham when you can get Alex Scott for £10 mil, what a bargain. Also bought Luka susic for £15 mil and loaned him back out. Those 2 and Bajcetic will be the future in midield.