Looking for some help, question regarding Corsair VS550 power supply and mATX case.

Solution
It will fit. The only time you need to worry about the form factor is when you're dealing with miniITX case or a PSU that is extended. Your PSU is a standard ATX PSU and will fit.




last question, I noticed that the Panther case comes with a 420 watt psu. can I replace it with the one I have selected out?
EDIT: apparently mine doesnt come with the psu.. which is good. Its cheaper. But is it standard atx?

http://www.1a.ee/arvutikomponendid_vorgutooted/korpused_jahutid/arvuti_korpused/spire_panther_midtower_matx_sp3205bcer

http://www.spire-corp.com/kms/images/uploads/spire_sp3205b-420w-pfc-1_01374648111.pdf