I have had good sucess with the C and D susato whistles, but mixed results with the low whistles. One low F was fine, pretty easy to play, but a low D was not, owing I think to the fact that some of the fingerholes were not symetrical, might have been made on a Monday.
You say you want a new one, just wonder what you have now?
I like the Clrake Originals for the price and they are quiet (Breathy) , so others in the area dont get quite the jolt you can deliver w a Susato.
My wife bought me an aluminum low g Cheiftan for about $150, I have big hands so no problems reaching the holes and I can play with the tips of my fingers rather than the recommended part between the first & second knuckle.
Susatos go for $20ish for the regular Whistles, $50-80 for the low, it has been a while since I bought one so I have rounded up to acount for inflation.
Have fun, you may know about the site below but it has a great selection of whistle music and it has tabliture if like myself you dont read music.
http://sniff.numachi.com/~rickheit/dtrad/
Whack Fall The Day
Nick