Hi there.  I am looking to buy some loop bundles over black friday.  I am new to using loops.  What file format should I be buying to use in Sonar if I want to change loop pitch and tempo?  I see Acid, WAV and more.  And I am a little confused.

similar thread http://forum.cakewalk.com/FindPost/3116417

Acidized will work in Sonar. Wav files, REX files, exc. Groove clips are Sonars native Acidized format.
but just about anything that works in other programs will work in sonar with the exception of some formats.
(for example: don't buy Kontakt samples unless you have the Kontakt player).