The little kid would win, he has The Master's Laser Screwdriver, while The Doctor's and their Clone/Daughter Jenny only have Sonic Screwdrivers, and The (I think) Steampunk Gentleman has the (Again, I think) Sonic Lipstick.
For this to TRULY be a Battle of The Screwdrivers they need The Doctor with The Sonic Screwdriver, The Master with The Laser Screwdriver, Sarah Jane Smith with The Sonic Lipstick, Ms. Foster (Doctor Who: Series Four: Episode One: Partners In Crime) with The Sonic Pen, and Professor River Song (Doctor Who: Series Four: Episodes Eight and Nine: Silence In The Library and Forest of The Dead) with The Future Augmented Sonic Screwdriver (Unfortunately Character Options hasn't made that screwdriver yet, so the cosplayer playing River Song could just use a regular Sonic Screwdriver and pretend that it's The Future Augmented one)
Actually I just recently found out that a British prop company called MFXReplicas is going to produce a replica of River Song's Future Screwdriver.
MFXReplicas makes props out of the same stuff they use in the movies and TV shows so the props are absolutely perfect clones of the real things that are used.
MFXReplicas make all sorts of props but they specialize in Doctor Who replicas because most of their staff is part of the Doctor Who/Torchwood/Sarah Jane Adventures SFX team, so they can use the original measurements and designs to make the props.
MFXReplicas has made Auton, Cybermen, Ood, Clockwork Android, and Roboform Santa masks, and are going to make some Davros and Sontaran ones too (YAY!), they have also made Sonic and Laser Screwdrivers, and Time Lord Fob watches, and lots of other good stuff.
Their website is currently down at the moment to update (or as it actually says on the site "We are regenerating")
I am looking forward to when it comes back though.