This is the follow-up of my previous posting regarding “Winscp in linux (KDE & Gnome)“. I’ve recently used a tool called Krusader (http://krusader.sourceforge.net/). This is the application that I found to be the closest match to WinSCP since they both are twin-panel file manager A.K.A orthodox file manager. Krusader have most of the features (maybe more) WinSCP had such as SSH/SCP connectivity, folder comparison and synchronization. Furthermore some of the hotkeys are pretty much alike.
From the official website
Krusader is an advanced twin panel (commander style) file manager for KDE and other desktops in the *nix world, similar to Midnight or Total Commander. It provides all the file management features you could possibly want.
Some screen-shots of Krusader