PCManFM (at least my currently installed version of 0.9.9 can connect to bookmarked sftp shares (described in my .gtk-bookmarks as "sftp://firstname.lastname@example.org/ shortcutName"). If I add sftp shares to my .gtk-bookmarks directly, PCManFM works with them just fine (I have ssh key auth). But for my girl I would like to see some "Connect to server" button that will show window where it's possible to specify type of remote server (sftp, ftp and other supported by ?GIO?).
I'm affraid my knowledge of gtk prgramming is not enough for implementing this by myself :(