I used the smaller gold Zalman heatsink for the chipset but the big blue on should work fine. I had to remove a few pins but this is very easy since the aluminum is extremely easy to bend/break with pliers. I think I ended up removing four pins. You could also just bend them out of the way. I wouldn't let the video card length stop you from changing the chipset heatsink but be VERY careful when installing the new heatsink. I would also suggest a very quiet fan since this NF4 gets incredibly hot. I just wrapped an old 60mm fan with zip-ties to keep it from catching on anything, then laid it up against the Zalman heatsink and used a speed controller to make it run verrry slow. Sure, this is the lazy way to go but it works perfect and makes almost no noise. I have measured the chipset heatsink temp from the top with a temp gun and it stays near 43c at full load.
About MSI and ECS boards, I have had some bad luck with MSI so I tend to avoid them. The ECS boards tend to be very good in my experience for a "set it and forget it" computer. If you plan on changing components in and out, and maybe doing a little overclocking, I would not suggest an ECS board except for maybe their extreme version(s).
Your 3800+ will work fine in the Foxconn board. The following is a quote from the motherboard manual (http://www.foxconnchannel.com/pdf/NF4K8MC-manual-eng-V1.0-02-05-05.pdf
) which clearly shows the 3800+ on the list. Also, just because a CPU isn't on this type of list does NOT mean that it wont work. The MSI is also reported to be a good board but it has no overclocking potential at all. The MSI does have onboard coaxial SPDIF output and 3 PCI slots where the Foxconn has no onboard SPDIF and only 2 PCI.
CPU Qualified Vendor List
The following table lists the CPUs that have been tested and qualified for use
with this motherboard.
AMD Athlon 64 3500+
AMD Athlon 64 3800+
AMD Athlon 64 4000+
AMD Athlon 64 FX-55
AMD Athlon 64 FX-53