Personally I use both. I have a Duron 600@ 770Mhz(7x110), setting the fsb/pci at 105/35 and the fsb+ at 5. The PCI+ is a good way to overclock your fsb higher without stressing the other hardware( soundcard,modem,vid cards, etc.)because it does't run the PCI & AGP busses out of spec., which can lead to instability, if you push it too hard.
As for voltages, the KT7 with the UL bios can be set as high as 1.85v, although the hardware monitor shows 1.92v when set for 1.85 on mine. It should be safe to run up to 1.85, at least from what I've seen, and as long as you have decent cooling(important), there shouldn't be any problems. Try increasing your speed in steps, say 50Mhz at a time, then increase your voltage when necessary, if you have problems with stability or crashes.
Temp wise, 49C is getting a little warm(actually a l'il hot), but acceptable under a heavy usage.(I'm sure some will disagree though) My current cpu temps run between 41-46C
with a system temp of 28-29C
and a room temp of 26C/79F, using a 14$ HS(cooler master). Now a couple of days ago when a cool front made it here to central Texas, the temp in my room was at 22C/71F and my CPU ran at
35-39C (cool

).