" if I want volume controls (yes I do) I will need logaritmic potentiometers right ?"
Yes, audio taper log pots, esp if using rotory pots, if linear slide pots then linear pots can work as you will probably be setting levels with a VM meter?
"whats the best op amp IC to use ?"
5532/5534 are time tested in audio applications, cheap and avalible and low noise...
" dual supplies? "
Yes, esp if you have multi stages amps/adders as it can allow you not to have to capacity couple between each stage.
Good luck