If you want a sword and board build that stuffs magic and buffs, it's actually quite easy to pull off by just equipping the Dark Silver Shield as your shield. It has an aura that reduces any magic damage you take or deal by half (when fully upgraded). You can even have it on your back while two-handing a bigger strength weapon and it will still basically nullify any non-fire spells or buffs.
If you're going to do this though I would recommend staying with the Crushing path instead of the Blueblood Sword (I believe the Knight's Sword is the most powerful straight sword, but I can't remember if it can go Crushing or not). The Blueblood Sword's biggest strength is in it's magic damage while buffed with Light Weapon, so if you're trying to avoid buffing or spells, you're going to be underwhelmed when you try it. Not to mention it requires very specific stat allocation to work at it's best performance, and if you haven't been working from the beginning for a BBS build you won't have the points to have an even semi-useful BBS without going past the Level 125 threshold.
As for the Moonlight Sword, in this game it's actually a Faith weapon. So really the only magic build that could incorporate it is a Talisman of Beasts build that uses a hybrid of Faith and Magic. As for the Moon Uchi, I can't really say. The only Katana I ever used in Demon's Souls was the Hiltless
So, long story short:
Don't go with the Blueblood Sword unless you plan on using buffs. For a tanky Knight build, you're best off with a Crushing Long Sword or Crushing Knight's Sword with a Dark Silver Shield. Also, you can't really use the Moonlight Sword well unless you're a Faith build.