I don't really have anything to add to whats been said in this thread so far other than to offer my personal experience. The Baker Sonic has been one of my Holy Grail props and, as far as I am concerned, you can do no better than the Rubbertoe Replica. My Quest is at an end. (At least until such time as the original prop resurfaces and they have a chance to examine it, lol)
For other options Russrep, as far as I am aware, is the only person that produces them regularly. Everything else I've seen has generally been a limited run. I've owned two RussReps and the BlueBox, researched the 1612, Time Lord's Pocket, et al, and while they are all generally excellent each has its peculiarities.