without thinking about anything else buy VinodGupta Sir'sNotes from POOJA Law House and also keep Singhania's book for reference.And please look no further.
IF YOU HAVE SUFFICIENT TIME, THEN MODULES OF VINOD GUPTA SIR ARE THE BEST REFERENCE BOOK FOR DIRECT TAXES.....
IT CLEARS CONCEPTS, CONSIST OF LAST FEW YEARS PAPER WITH AMENDED SOLUTIONS, LATEST CASES, CIRCULARS, AMENDMENTS AND REASON FOR AMENDMENT, BARE FINANCE ACT....ETC....SO GO FOR IT....ITS D BEST....