I have a GF2 Pro which have been modified. The stock heatsink+fan was replace by a large heatsink.
Right now it has an idle temperature of about 65 C and reaches 70-75 C when playing intesely.
But I have put an 80mm fan which blows air over it which brought the idle temperature down to 28-33 C.
The new chassi I am buying will have a hole in the side for a fan that can blow air over the expansion cards.
So, no need to worry about 49 C. I think my previous Asus GF2 idled around that with the retail heatsink and fan.