What a peculiar thing to do?
Nothing you have described so far operates at anything other than 5 V, so I cannot imagine why you would want to use some 9 V supply!
Not only that, 5 V supplies to provide this sort of power are readily available, 9 V supplies are not!
55 mA per pixel times 100 suggests 5.5 Amps, so a 5 V 6 Amp or 10 Amp supply would be appropriate. While I know computer power supplies are commonly rated to 5 or 7 Amps output and have a 1 metre or so cord to the PC, running that sort of current at 5 V over any significant distance sounds like a bad idea, better to use a supply located near your display with a mains cord to the wall outlet.
You do seem to be very new to this if you do not know how to practically connect things in parallel. Perhaps you should better describe the overall purpose of this so we can advise on the construction.