The lady at barkingdogclothes (Rena) will custom make anything for you. She has two pages of fabric selections and you just give her the measurements, style, and fabric you want and she'll make it for you - at incredibly reasonable prices too
I'm pretty sure that all of her shirts can be made without the sayings and stuff. She's really nice, if you drop her an e-mail I'm sure she'll let you know!
http://www.barkindogclothes.com/