OK. Than I would guess pcmanfm would do. I guess you are trying to cater to the newer user with this derivative.
I've been using Slackware for 7 or 8 years now and although I might mention it to a newer Linux user I would never suggest
they start out with it without trying something else first ...

There was an update to SpaceFM at the end of March 2014.
Has anyone looked at XFE as a file manager? Very light and fast. It does look old school but is very functional. I use it all the time.
There is a SlackBuild if you want to try it out. If you want you can download the newest version (1.37) and ...