Printing music parts and scores

[Jeremiah Reilly]

Lilypond does a fantastic job engraving music. I want to print up high 
quality parts and scores for my music. Parts would measure 9x12 inches 
(apologies to folks outside the USA) or 10x13 inches; scores would 
measure 10x13, 11x17 inches, or larger even. Paper would be heavier 
weight (80 pound). Basically I am looking for "standard" music paper. 
What have you used to print your music for parts and scores? I live in 
a remote rural community. I have searched the web for a music printer 
without success.

Has anyone ventured beyond 8.5x11 inches or A4?
What have you done?
Can you refer me to a printer?

much obliged,

Jeremiah