There is really no way to guarantee an album will have gapless playback when uploaded to the different stores. There are various reasons why. For one, each track is made available for individual download on an album (with the exception in iTunes if a song is longer than 10 minutes, the song will automatically be made available for sale as 'album only'). Also, the stores cannot control a user's personal audio playback settings on their computer or MP3 player.
The only possible way to guarantee gapless playback would be to upload an album as one long track, which you can submit as a single. One thing to consider though is that again, iTunes does mark any track that is over 10 minutes as 'album only' which therefore sets a default price of $9.99. No other stores do this so it would most likely have a price of $0.99 outside of iTunes.
You are able to change the price in iTunes only after you've distributed to stores. Learn more .