My son, Celt_Gravity Rebel is around 5'4 and wears the large youth kilt from Stillwater.

He uses the youth sporran from there, and also has a cell phone case he clips on his belt. (It's difficult to see how small his sporran is because he personalized it by gluing a deer tail on it.

You may want to consider the Nightstalker Sporran from Stillwater . It's a bit on the large side, but it's practically a cartoon bag as far as how much stuff you can actually cram into the thing.

My husband (5'7") on the right is wearing the nylon Nightstalker cargo sporran in this photo (son is on the left, with aforementioned deer tail sporran)