I've ordered from a number of places over the years with varying success...
Getofficial.com - out of KC, MO. I've ordered before in the morning and had stuff the next day without paying for expedited shipping.
Ump-attire.com - have had good luck with getting stuff from them relatively quickly.
Honig's - Good success
theofficialschoice.com - NEVER EVER ORDER FROM THERE AGAIN.. they usually have great prices on whistles, but it then takes forever and a day to actually have it delivered.