Serious performance problems with Bukkit 1.4.2-R0.1

Hi,
everything is running normally untill the number of players goes over 80+- . I´ve got about 130 people online and then TPS goes rapidly down up to 0.3 TPS.
It is still playable except player movement (seen from another player point of view) and pvp system, which is one of the main things on the server.
Currently I am using these plugins:
CraftBukkit on Bukkit 1.4.2-R0.2-SNAPSHOT:
MultiWorld 4.2.0;
WorldBorder 1.5.4;
PlgDisableCmd 2.0;
AlphaChest 1.13.0;
WorldEdit 5.4.3;
Websend 1.5.1;
LogBlockQuestioner 0.02;
Vault 1.2.19-b248;
PermissionsEx 1.19.3;
AntiRelog 2.0.0;
Stargate 0.7.7.5;
LogBlock 1.60;
UltraBan 1.0.1;
LWC 4.3.0 (b736-git-1b1150b1) (August 08, 2012); CapsGuard 2.0; WorldGuard 5.5.4; RemoteToolkitPlugin 0.61;
BeardStat 0.4.8-Ice Cream-git-jenkins-BeardStat-32;
ZavAutoMessager 1.9.1;
DrugMeUp 0.5.3;
MobArena 0.94.4.81;
mcMMO 1.3.11-b1030;
MultiHome 0.15;
Essentials 2.9.4;
LagMeter 1.10.0;
Jobs 2.8.5;
MobCatcher 3.0 Dev;
XrayInformer 2.2.0;
EssentialsSpawn 2.9.4;
ChestShop 3.46;
EssentialsChat 2.9.4;
Residence 2.6.6;
Factions 1.6.9.1;
AntiCheat 1.4

Which of these is from your point of view the problematic one?

Thanks for your help!