Using a shield is ok for PvM, but not as ideal as using bushido. Here are some benefits of using both bushido and parry, as opposed to just parry:
Honor/Perfection - with bushido, honoring your opponent will cause you to gain "perfection" with each successive hit. Each time you gain perfection, your damage output increases. Achieving perfection will result in 100% damage increase.
Weapon Parry - with bushido, you can parry with both one-handed and two-handed weapons, whereas if you only have parry you are limited to using one-handed weapons and shields. With bushido, using a one-handed weapon will also allow you to drink potions.
Confidence - the bushido confidence spell is another method of healing.
Momentum Strike - the bushido momentum strike allows you to attack two nearby opponents simultaneously.
Evasion - the bushido evasion spell allows you to evade damage, including magic damage.
Lightning Strike - the bushido lightning strike maximizes your hit chance increase and will occasionally allow you to inflict critical hits, which will deal more damage than normal hits.
As you can see, most players prefer to use both parry and bushido so that they can benefit from the items mentioned above. Also, you will want to use power strolls to raise some of your skills above 100s. With only 100 swords, it will be nearly impossible for you to hit mid- to high-level foes. Moreover, with only 100 parry, you will be hit too often to remain viable against higher-level creatures. Finally, you will definitely want the chivalry skill for PvM. Chivalry allows you to increase your damage output, provides you a method for travel, and allows you means to heal, cure, and remove curses.
For PvM, I'd suggest something like this:
120 weapon
120 bush
120 parry
100 tactics
100 anat
90 healing
70 chivalry
Or, for a more cost-efficient template (i.e., for newer folks who can't afford scrolls):
115 weapon
115 bush
115 parry
110 tactics
100 anat
90 heal
75 chiv
If you prefer to forgo the benefits of bushido, then perhaps something like this:
120 swords (or 115, for cheaper option)
120 parry (or 115, if you can't afford the scroll)
100 tactics
100 anatomy
90 healing
75 chiv
120 Points to distribute between perhaps your current skills, magic resist, or meditation. If you chose to use magic resist, you'll want to bring it to 120 (or 115 if that's all you can afford), else it won't prove very effective.
Here is some additional info about bushido:
http://uo.stratics.com/php-bin/show_content.php?content=30726
Here is some additional info about chivalry:
http://uo.stratics.com/content/guides/paladinabilities.shtml
