Yes the Corsairs are ok .I wouldn t worry about the lack of support in the memory supported list
Practically i have never found the exact RAM manufacturers put in those lists
On the other hand i can t recommend you the usage of a motherboard like the one the reseller is promoting ,with a six core CPU.
Mainly because the chipset is old ,the power stage has no cooling and you won t have SATA 3 support neither the option of USB 3.0.
SATA 3 support is on the AMD 8xx chipset family and up .
In theory the X6 CPU has the ability to run 1600Mhz with it s IMC ,my PII X4 975 is running right now at 1600Mhz with some Geil RAM .
Keep in mind the X4 has a little crappier IMC than the X6 in spite of being in the same Phenom 2 family (X6 has a newer silicon revision).
Overall the system you are building ,needs no more than some 500W (more than 36Ampers on the 12V rail continuous) quality power supply .If you intend a better video card then maybe something like a Corsair 600W/650W with around 50 Amps could be a little more suited ,just to get the PSU loaded where it gives the best power efficiency and the lowest noise and heat.
For gaming though - I am not familiar with Planet Siide2 though - a X4 CPU should be more suited ,higher clock rates per core.
Unfortunately most of the games and software are not optimized for six cores yet ,even now.