If your linear pot is giving you a log response, and you want a linear response, you will need an anti-log pot. These are not common – they are usually found as part of a stereo balance control, with a log/antilog dual pot.
My suspicion is that you are overthinking things – try what you have, and you will find it fine in a little time. The control laws for the controls are not documented – my guess is that some are log, and some are linear. It depends on what you are trying to do.
