The S5's problem, to me, is that I consider 35/36mm equivalent at the wide end unacceptable. 28mm-30mm is a minimum in landscape photos IMO. You can most certainly get the wide converter for the S5. The S5 has AA batteries as an advantage though.
That said, the G9 seems to score a bit higher in reviews, probably due to the larger sensor. However it's tele end is not as big as the S5. You will also need a wide converter to get a wider angle.
Panasonic FZ18 seems to have the zoom range, but noise is always a problem with Panasonic's cameras. DCResource
suggested to shoot in RAW mode if you care but you may not want to dabble with that. Speed is often good with Panasonic's cameras though.
Olympus and Fujifilm also have similar models that you can look at. The Olympus long zoom model seems to be stuck with xD card so that is out for me. Fuji is famous for its low light high ISO pictures but if you are shooting mostly outdoors that may not be a factor.
The Model M is not for the faint of heart. You either like them or hate them.
Gerbils unite! Fold for UnitedGerbilNation, team 2630.