I found and excellent program to get maxed horses and weapons. This program is basically a save game editor that modifies your save data. Be sure to make a backup for your save data before using this program. The save data is located in My Documents\KOEI\Dynasty Warriors 6. Also, this program requires .Net Framework 2.0 which can be downloaded from microsoft website. Just google .Net Framework 2.0 and you will get it.
Using the save game editor, you can modify your weapons,horses and even your character's level. For level up, just change character's experience.I suggest not to unlock skills using this program because game needs you to spend every skill points you have to continue. If you unlock all skills before you reach level 50, then you will be stuck at skill screen.
The link to download the save game editor is
Just download it and have fun.
DON'T FORGET TO SEE ITS HELP SECTION BEFORE USE!!!