The cheap option is to find a bottle you like and make a hole in the screw cap with a drill/knife whatever, and stick a 10mm plastic/silicone (food/drinking approved) drinking tube down the hole . (Buy a roll of eg 10mm drinking tube at your local boat equipment store)
You easily have a perfectly working drinking bottle within 5 minutes for less than a dollar/EUR - or little more if you find a flat/square bottle you like in the store. This also eliminates the problem of cleaning out dirt/mould which come quicky with sports drinks
Having said this the Fenn bottles are nice and practical - but requires lots of cleaing to be reasonably germ/mould free
Current skis: Epic V10 G4, Epic V12 G2, Fenn XT
Earlier skis: Knysna McGregor Classic, Fenn Elite S, Nelo 600, Fenn Elite, Fenn SL, Nelo LD (2010-ish) Fenn Glide, Think Evo, Think Legend