Which Small distribution I would chose on a USB Persistent image

 1. Easy OS

Not really. Lot of limitations in applications

No Synaptic Package manager

IGB

2. AntiX OS

Probably yes.

Lot of window managers 

Has synaptic.

I.9GB

3. MX Linux

Based on AntiX but it has KDE version which solid

4. Legacy OS

It was TeenPUP and not anymore.

Plenty of application and based on AntiX

Has synaptic.

3.2GB.

 I decided to go for AntiX.