I'll be working on a map importer so I can import tiled maps into orange-edit.  For now, Tiled is stable in Windows.

If you can, use the existing tilesets contained in the orange engine download.  That said, at the moment there aren't many in there, so if you need a new tile set, go for it.  Scale it x2 without any filtering so the pixels will stay pixel-y.  :)