In the Biab Plugin if you don't have a RealChart or Midi track you can drag into Reaper generate one up then drag it in importing the tempo map.
Using Biab Tempo Change Songs in the Plugin then use "Biab Plugin Chord" after you have the map.
To get the wav to fit the tempo map in Reaper:
Reaper > Preferences > Media > Video/Import/Misc > After adjusting tempo, set imported media to auto stretch at tempo changes..
If it is not Acid (not sure if Acid is working in the Plugin) or it doesn't pick up the tempo from the filename then to set it manually right click item > Item properties > Playback rate [Set] set to the tempo of the wav > Item timebase > Beats (auto-stretch at tempo changes)> Ok > No
No not in ReaPack yet just check the forum link for updates.