That size should be good.
This is a sticky in the kegging forum about the different sizes.
It really just depends on the hump location, if it has one.
Double Dog Brewing
Keg 1- Schitzngiggle Oktoberfest
Keg 2- Flat Tire Amber Ale
Keg 3- Twisted Pumpkin Ale
Keg 4- A Night in Vegas APA
Bottled- Summer Saison, Bohemian Dunkel, Second Shot Irish Ale, The Kraken Barleywine
On Deck- Schwarzbier, Snooty Fox Brown Ale, HOP-Head IPA