Hi, welcome, and best of luck. Full tails are fine, but white is not 'Standard' coloring for the Yorkshire Terrier breed. 'Standing' ears are among the 'correct' genetic attributes spelled out in the breed club's Standard...the Yorkshire Terrier Club of America (YTCA).
White coloring and floppy ears are both adorable, and my golden Mia is spectacular in color...but oh so wrong for color...LOL. It is a color fault...she was born black and tan but the black all was replaced by gold when her color changed. My kids are not breeding stock so it makes no difference in them...in their breeding parents, it certainly should to their breeders...LOL. My part, however, is to provide love, lap, and years of devoted service to my Yorkie babies.
Best of luck! You will make a right decision for you...and hopefully share your next baby with us here...hint...hint...