Claiming CB & TC for one child each has worked out well for me, although my ex probably won't agree as she was getting all when we were together. However she would be unable to deny that we've done it the only fair way considering we look after both children week about on a 50/50 arrangement.
However, if I understand this right, your son wishes to live with you 100% (or at least the majority) of the time, and your other child would stay with you for say 50% of the time, then I believe you would be classed as the Parent With Care as you are looking after them more than 50/50, and would therefore be entitled to claim CB & TC for both children. As far as I see she would also have to pay CSA rates of maintenance, reduced depending on how often the children live with her.
A MASSIVE THANK YOU TO EVRYONE WHO HAS TOOK THE TIME TO REPLY TO ME.
ITS BEEN A HARD HARD 6 MONTHS BUT I CAN JUST ABOUT SEE THE LIGHT BEGINNING TO SHINE THROUGH AT THE END OF THE TUNNEL.
STBX I BELIEVE IS IN FOR A RUDE AWAKENING SERVES HER RIGHT(WHAT GOES AROUND COMES AROUND).