cpu temp questions

I am new at overclocking and just put a new machine together. Running at stock speed I am getting different CPU temps. I want to make sure I understand the temps before I try to OC. I have made no change to the default BIOS settings 1.5v.
setup:
MSI P6N SLI Platinum
Q6600 B3
Theralright Ultra-120 eXtreme
case Antec nine hundred

I am running prime95 to stress the system (about 20 mins).

SpeedFan 4.33
Temp1: 40c
temp2: 33c
Core 0: 35c
core 1: 35c
core 2: 35c
core 3: 37c
flame Core: 55c

Core Temp 0.95.4
Tjunction: 100c
Core #0 58c
Core #1 56c
Core #2 51c
Core #3 51c


DualcoreCenter (MSI utility)
CPU temp of 41c (came as speedfan)

Idel times:
Core Temp: CPU 40c 38c 33c 35c
SpeedFan : CPU 20c 20c 20c 20c


As you see the Core Temp shows a lot higher temps and I am worried that I can not over clock it. Another thing that worries me is that Core Temp and SpeedFan do not give the same numbers. What program should I use to monitor my temps? I been reading everything from bad CPU to bad Ultra-120 heatsinks. I thought that I got a good heatsink and it worries me that my temps are so high at stock speed. Help, I am really confused. Let me know if you think I have a heat problem.

thanks
Matthew