Salvage yard would be a good place to look for a washer tank - just look those up in your local yellow pages or an online search. There are some online resources for used/salvage tanks - places will remove them from donor vehicles and ship them to you. Problem with that is shipping is usually much more than what the part would cost you. I can't really suggest any off=hand - as I don't know what area you are from.
2002 Corolla S, Silverstream, 1.8L 1ZZ-FE (VVT-i)
2003 Matrix XRS, Cosmic Blue, 1.8L 2ZZ-GE (VVTL-i) - RIP
2009 Matrix XRS, Blue Streak, 2.4L 2AZ-FE (VVT-i)