Just wanted to plug this guys kit:
Windshield Washer Tank Relocation Kit — Silver Rhino Media
No idea if he is on the forum here, but I bought his kit as I was tired of my 255's rubbing against the stock washer tank. His kit installs really nice, retains both the front and rear washers, and includes the metal brackets and things you need. While it is just a simple Dorman reservoir, its big enough and the metal bracket it comes with holds it in place really well.
Worth a look if you are running an aftermarket bumper, or like me are running a big enough tire you are rubbing there.