If it is for cd or universal media player format you ditter and save your mix to 16 bits 44.1.
If it is for archiving or postmastering (if you send it to a mastering company) you bettter render to 24 bit or higher, samplerate same as project audio (no conversion), no exessive limiting or maximizing (yet
) if possible.
In general: as long as you don't compress (mp3) or use DRM (WMA) , most file formats are "sort of equal" as you can always convert. Lossless (Flac) is also fine as you can restore to uncompressed audio at wish.
Studio: Cubase 6.5.5 (& 7.5) 32 bits
on Windows 7 64 bit.http://www.soundonsound.com/sos/nov10/a ... 64-bit.htm
Intel I7 4930K @3.4Ghz/Asus P9X79/16gb/NVIDIA GeForce GT 610/2x RME Digiface PCI
Intel Q6600 @2.40Ghz /Asus P5K/4gb/NVIDIA GeForce 850 GT/RME multiface PCI
Ipad2/16gb, Lemur running customized 16channel Mackie control and multiple 14 bits generic remote templates, presonus faderport, BCR2000, 2x BCF 2000