Rebuilding Speaker Cabinet

[Oddity]

Hi there,

I have an old pair of Yamaha PA speaker cabs that have 4 12" speakers (8ohm, 40W) and a 4x10 horn (8ohm, 20W) in them. One of the horns is blown, and the speakers themselves are old and muddy sounding (I think these were built in the 60s). The cab is rated to handle 100W max, and I'm looking for more power, and a crisper sound.

What I'm looking to do is rip all the the speakers and the two horns out of these and replace with some new speakers/horns that will really push some sound. These will be used for live music performances, mainly vocals with possible mic'd instruments. I'm looking for a good sound, but not really hi-fi/boutique quality sounding stuff (I want to try to keep this project as cheap as possible, but I do realize it wont be "cheap" . I'm hoping to get at least 400W/cab in the end, and have as full frequency spectrum of sounds as I can.

What I need to figure out is:

Where would be the best place to purchase some decent speakers/horns for this application, and what kind should I get. Should all the 12" speakers be the same? Or maybe two that are more bassy, two midrange? (horn I assume will cover high end). I've done a lot of searching online, and found many places to buy many kinds of speakers, but I'm looking for recommendations. I'm in San Jose (San Francisco Bay Area) if anyone knows of any good local shops.

Also, there is a small circuit board with 3 power resistors on it in the cab, and all the cables run into/out of there. I'm guessing I'll need to replace these since I'll be using speakers with a much higher power rating (I don't want to cook them). It's a very simple circuit, but if anyone had a link or couple type up a small schematic that would be great. I don't know the exact power handling of each speaker yet, but would be most likely be 8 ohms.

Thanks!