Gnome is quite heavy, before you succumb to the void of choosing the best prompt format, try some other, lighter WMs. I like Fluxbox very much; XFCE is lighter than Gnome/KDE but still similar; i3 is also lightweight.
I guess there might be some light Firefox forks, or maybe even go back to iceweasel?
As for command line, check out:
tmux
zsh (it’s completion mechanisms are imo better than bash)
mc
how to define your shortcuts as functions inside every login shell, instead of using aliases which are easier but have limitations
Btw, slackware still maintains x32
And there’s also arch32