I like the 30 long for my QT tank. Has plenty of room for hang on power filter, powerhead, ato, temp probe and heater plus I can also put a tunze hang on skimmer if I like. Easy to siphon out food and detritus too.
The larger the better. This isn’t scientific in any way just IME keeping params stable in a 10g is a nightmare especially if you have to add medications.