I actually got rid of my 360 a few months back or I would try to help you. :/ I didn't know anyone still played the original Dark Souls. Best of luck.

Plenty do

Omg I wish I could help! Four Kings is no joke D:

3 tips for NG+:

-No beatrice, cause her DMG-Output is lower on NG than on normal game, but the 25% more health on the kings are something,
-look for a fitting weapon/ self enchantment: sunlight sword or iron flesh can come a great way (iron flesh cause of resist when close to the king as he does not hit hard then. Fast kill needed though)
- definitely go for some medium armor with good magic- and phys-resist. Brass is a good set for that.

Also: what build are you actually?

How I beat them on NG+ and NG+2,3 etc. was to use full Havel gear, two hand your weapon, (I used a +15 uchi), self buff, like darkmoon blade or sunlight blade, Power Within pyromancy, then R1,R1,R1,R1 XD they go down so fast then :)