Headphones/live room monitoring system question

[6dyslexicelephnt]

Hi my home studio just got started and over the weekend I was embarassed to have only one real pair of headphones (couldn't find the the other crappy pair) and they had to use a pair of busted ipod headphones out of my borrowed samson headphone amp for a band of 6 people (luckily not all tracking at once). So I decided to invest the money I got from the weekend ($150) and some of my own cash into a sweet headphone/monitoring system for the live room. Here's what I'm thinking...

Furman HA-6AB 6 Ch. Headphone Amp with 20W speaker output (ebay) ---- $150-200
AKG K44 3 pack on ebay (usually $30 each) ----------------------------------- $49.95
Some nice thrift store speakers like Marantz ---------------------------------- $16
Headphone extentions and speaker cable --------------------------------------˜$20

I need a solid system for the live room that will last for recording lots of bands in the future (I hope)

Is this all going to work together nicely? Specifically I was wondering what 20W sounds like and if it would work with some thrift store home stereo speakers for live room playback. Maybe I would want to put an EQ before the speakers to compensate like my cheapo Urei 537? I was thinking of putting the speakers in opposite corners as the room is a long rectangle (is this a bad idea?).

Also the K44 look sturdy... has anyone used these for studio work? How much can you hear what they're playing outside of them? I was having some problems with feedback with loud crappy headphones and the vocal mic. Anything else you would recommend in that price range?

Thanks for you help!