Of course it is worth it to mod a PS2. It gives you the ability to play import games, homebrew stuff, it allows you to use backups of games you own - - well yo know all the good stuff, if you been on the Xbox modding scene, it should be similar.
There are a lot of good chips out there, I believe that most now have their own website.
Also if you go to the BST vendors area, you will find that there are websites by the vendors who have descriptions and installation diagrams for the chips.
Here are a few chip names that you might want to check out: magic V, DMS3, DUO, matrix, messiah2, etc.
Good luck researching, all the info you need you can probably find on these forums.
NTSC/J SCPH 30000 V4 No Gap
DMS3 V2 FW2.3b3
40GB Maxtor HDD