more books more confusion,less books less confusion,1 book no confusion.
just go for 1 book which you have decided and complete it.
isca dinesh madan is better than velecha becoz-memory codes are helpful only if you know the concept,we are writing professional exam and not mugging up anything,so be clear in concepts and you will develope all codes yourself.
dinesh madan is a good book,velecha is too precise,more over in ca final its more about the content of the answer and not just memory codes.