If all your debts are separate ones, then you can keep them that way if you wish. If you have any joint ones, then if one of you enters an IVA, the other one will still be liable for that debt.
In an IVA, the dividend is the same to all creditors, so if you are paying 50p in the pound, they all get that.
In a Debt Management Programme, the creditors are paid pro rata.
Sharing from experiences of dealing with debt
The greatness of a man is not in how much wealth he acquires, but in his integrity and his ability to affect those around him positively.
Bob Marley. http://kallis3.blogs.iva.co.uk