assuming it's Killzone 2 that i want to get the dlc for.
my Killzone is region 2 BCES, and my ps3 is also region 2.
so which type of PSN accounts should i use and which psn prepaid card should i buy???
p.s: whenever i go to uk.playstation.com to make a UK account, it redirects me to eu.playstation.com signup......which is getting me REALLY confused about what to do
It doesn't matter. As long as you have access to that account on your PS3, you should have access to the DLC. If the DLC is in another person's name though, you won't have access to it. But if it's in your name and in your download list on your PS3, everything should be fine.
I do not know specifically about KZ2, however most posts on the EU Blog indicate that the DLC must be from the same region as the game. Meaning a US PS3 can play the EU version of a game the DLC needs to be the EU version to match the game.