The Mace of Disruption, the Flail of Ages, and Crom Faeyr aren't good enough for you?
I suppose you might picture your Fighter/Cleric as an avenging angel of doom with a flaming sword, but if that's the case, I wouldn't settle for anything but a flaming sword. How about a Moonblade?
I don't understand what you mean when you say that you found that you can edit a cleric to use swords. Does that mean you equipped the sword with Shadowkeeper? The problem with that is that you can't re-equip the weapon if you drop it for some reason, for example, if you switch weapons or try to use Two Weapon Style and then try to equip a ranged weapon. As I said earlier, the only way I know to allow a Cleric to use a sword is to edit the item. Items have flags which determine which classes can use them. If an item won't let Clerics use it, then the only way to allow your character to use it properly is to change her class, but that would defeat the whole purpose. That would mean the tail is wagging the dog.
A Blade might be a good choice for you, but you would probably play it as a Fighter/Mage. At higher levels, you might prefer a Fighter/Mage, for a variety of reasons. But Blades are fun to play, and they have some tricks of their own. For example, Offensive Spin combined with Melf's Minute Meteors will serve you well, especially at lower levels. If you want the Bard stronghold in Shadows of Amn, I suggest that you make your INT and CHA as high as possible (19 and 17 respectively). As Coot pointed out, they won't affect the number of spells that you can memorize.
From a roleplaying point of view, I can't think of a compelling reason to keep any of the NPCs with you in BG1. There simply isn't anything that binds you together until you play Shadows of Amn. But I enjoy the company, and I like having their skills at my disposal. If were playing a non-Thief character, I would not attempt Durlag's Tower without a Thief in my party. If I were looking ahead (with knowledge that my character could not possibly possess), I'd take Imoen with me in BG1. But to some people, she's annoying.
When you play Shadows of Amn, you can ignore everyone but Imoen in Irenicus's dungeon (just pretend that Minsc and Jaheira don't exist). After she is kidnapped, you can solo Chapter Two and Chapter Three, or you can let Nalia join your party when you do the D'Arnise Keep quest, or you can let Keldorn help you with the Unseeing Eye quest, or you can let either of them help you with the Windspear Hills quest (I like to pretend that they have a personal stake in that particular quest). If you want Haer'Dalis in your party, I would not attempt the Astral Prison quest without some kind of help. Have you let Haer'Dalis romance Aerie? I think a Swashbuckler, Haer'Dalis, and Aerie would make an interesting party--a dashing troop with a flair for the dramatic.
If you look at the experience figures I gave you earlier, you can see what sort of levels to expect. For example, if you take one NPC with you in BG1 (such as Imoen), they'll both have over 600,000 experience points by the time you finish the game. They'll be more than powerful enough to beat the game. If they were any more powerful, it would be a cakewalk. For example, with proper buffing and invisibility, Imoen can backstab anyone to death at 9th Level. She can't do that in Shadows of Amn, which shows that BG1 was not meant to be played with characters over 7th or 8th Level. So I don't think it's desirable for one character to earn over 1 million experience points. By the same token, I don't think you should finish Shadows of Amn with characters who have more than 4 million experience points, because the final battles just aren't challenging enough with characters like that, and Irenicus is not supposed to be a pushover. Of course, if you install the Tactics MOD or other MODs to make the game more challenging, then what I said does not apply. But my point is that even if you have one or two NPCs in your party, your character will become very powerful--powerful enough to suit me, anyway.
