[xVIP3Rx]

I think, it does not matter, if you wanna use less ram you probably have to use less variables in your script
(as far as I know)

But you shouldn't worry much about ram, people say 512 if enough for a server.

Adding your code to a filterscript or gamemode will consume the same amount of ram, but I think gamemode run codes faster then a filterscript, thats the only advantage I see.