Kali Linux on portable SSD with data persistence

I need to setup a portable kali-linux environment that I can boot on any available computer. I don't want to use a virtual environment because I would need to download VMware on the host computer, plus it's not practical since I will need to boot my OS on friends/customers computers. I just want to boot it from the BIOS, do what I have to do and leave without changing or downloading any files/software on machines that aren't mine. I want to leave the hosts like I was never there after I'm done. Of course, I need data persistence so that I can access, change and keep my datas across reboots on different machines. So, if I'm not wrong, what I need is: Adding Persistence to a Kali Linux Live USB Drive Making a Kali Bootable USB Drive (Windows) I have two questions: - Wouldn't something like that run too slow on a classic USB flash drive ? - I kind of want to use a portable SSD for this. I found one that I like and I'd like your opinions on it and if what I want to do with it is possible. Since this SSD has built-in features and software, is it going to be a problem to make it a kali-linux portable environment? For example, what if I need to format the disk to a specific file system type?