Sorry guys, no cigars here.
CD-R is Orange book. Orange book supports redbook which is audio, yellow book which contains cd-rom data, such as video, jpegs, .mov's, aiffs etc., blue book which is enhanced cd, cd+G and cd extra. Green book which is CD-I or cd interactive, games, driving direction progs etc. fall under green book or white book which is original video book standard. Redbook is the "audio" spec and orange book, just means that it's cd recordable one time and can contain all of the above book standards. If you send a cd-r with 16/44.1 audio to a rep plant, it's red book specs on a cd recordable orange book cd. If you send a 24/44.1 audio file to a rep plant, than you are sending a yellow book file on a cd recordable orange book cd. They would have to WLR it to 16/44.1 which is the bit depth and sample rate spec for redbook audio cd's, before it would fall under redbook specs. Don't be confused into thinking that you must send a rep plant a redbook cd, it's up to them to adopt to the redbook standard, not you. For example if you are going to get the mastering engineer at Discmakers to master your material and their plant replicate them, you may want to send 24 bit files. They would master the files at the higher res and WLR to meet redbook specs after processing.
I don't remember there being an audio limit on the length, but most rep plants won't guarantee going over 74 to 76 minutes and some make you sign a waiver, holding them unaccountable for any failure's on over 76 minute cd's.