I have been running my Yellow top for about 6 years now and a buddy of mine bought the gel cell from CTC when it came out and its screwed already. You get what you pay for.

 

Any of those will work well. You must be playing you system loud to only get 20-40 min of play time on less then 70amps of current draw. when you do do the battery upgrade, defenatly do the big three upgrade like 1loudscort00 said. you probably only need to do 4ga for that though. Unless you plan on getting bigger amps.