You will probably be fine. I believe that MSI card uses ATI technologies, which is pretty standard.
In fact, you've probably got a lot more power than you need here -- if there is such a thing. So you should be just fine for editing pretty much any kind of video.
About the only challenge is that it's likely this machine will be running Windows 7 64-bit. The 64-bit version of the OS is going through a bit of growing pains right now, and some people are finding it presents some challenges for current versions of Premiere Elements. That may well change with the next generation of the program -- but I can tell you from years of running this forum, the vast majority of problems I've been seing this past year are from people running this program on Windows 7 64-bit.
That's not a death sentence by any means. There are no doubt lots of people not having any problems at all -- and that number will likely go up as the operating system and the program evolve. But right now, it's a caveat for any new computer buyers.
Welcome to the forum.
You might want to take a look at this ARTICLE on What PC Should I Buy/Build?
My comments are any current video card, with good driver support (nVidia, or ATI) will do nicely for PrE, as it exists now. The driver support is paramount.
I would look into adding a non-RAID system HDD for the OS and programs, and not have them on a RAID. An Array will speed up I/O with media, and with Projects, but separating the OS & programs will very likely give you more bang for the $.
For AVCHD/H.264, the biggest improvement will come from a very fast CPU.
[Edit] Again, Steve's reply was not showing, and it was posted well over an hour ago. Interesting.
Thanks for the explanation, also thx to Steve.
I still have an 1Tb HDD in my current pc, so I can take that one out to use it for the OS.
The other 4 HDD's will do better in RAID 0+1 or not ?
Is the i7 2600 fast enough for AVCHD ?
I think that the 2 HDD setup will be better than just the single RAID, as the OS sees that as a single HDD. Splitting the I/O load is the way that I would go, and you have that extra HDD already.
As for the i7 2600K, I really do not know. Though it uses PrPro CS5 for the benchmarking, you might want to take a look at the results for various CPU's (and disc setups) HERE.
Good luck, and hope that there is some useful datat in the PPBM5 spreadsheet.