The bladesinger has a long history in D&D:
First printed in Tome & Blood, and then soon after appeared again in the T&B web enhancement, as they forgot a lot of abilities in the book.
Later, in Races of Faerûn, they released another one, this time you could choose between long sword or rapier.
Finally, the 3.5 version in Complete Warrior, moving away from the separate spell list and giving it 1/2 spell progression, as well replacing that "free casting of spell with full attack" with a sudden-quicken like option once per day (only spells up to 2 or 4th level, depending on level).
Personally, I'd allow them to use whatever one-handed blade they want - short sword, long sword, rapier, scimitar, elven shortblade, elven thinblade exotic bastard sword, you name it. As long as it's a one-handed or light weapon (so the elven courtblade is out)
As for other kits: A lot of them appear as PrC's in one book or the other, and anyway, most of them don't really need a PrC, with 3e-Rules you can create them just fine. (Assassin, for example, can be created quite easily, the PrC in the DMG is something different, using spells ans stuff).