Internet radio show in a shed (Help?)

[XIXStudios]

Hello all,
 
I am currently setting up a new little radio show (internet & pirate) in my backyard shed which will also be a listening room for 90% vinyl.  I've done a show for years but always at a studio with the equipment set up so here is where I need some help.
 
I understand I will most likely need to make the listening room and radio broadcast part two separate things (with some shared equipment) mostly because I'd want studio monitors for the broadcast and a nice tube amp for the listening room.  I want the sound quality that goes out into the world to be superb and lossless.
 
So I guess here are my first questions and any help would be hugely appreciated.
 
Do the mixer boards have any affect on the sound quality?
 
Do I set up a pre-amp and an amp to the mixer or is the amplification done in the mixer?  
 
Do I go straight from that mixer into a computer to send the signal out?  
 
I know a lot of these questions can be answered online but I'm having trouble finding info on making it the best quality sound possible.  Most info is on just getting a signal out there.
 
Thanks,
Jeremy