[KeithMoonwannabe]

quite honestly what is lacking in your actual recordings now?

because I own and use the EMU 0404 usb and the preamps and converters will probably be as good or better than any interface suggestions you will get (I read the ones you got so far).

If you are looking for a character pre than upgrade the pre. But the actual XTC pres built in are pretty good low noise, good dynamic range, decent amount of headroom pres, they even have built in limiters and 60dB of gain should easily handle your SM7b unless you have a really really quiet source in which case you'd need a really good pre that's quiet all the way up to like 70dB of gain.

As far as the headphones go you could be spending some hefty cash to get a good headphone amp. Check out some audiophile sites/stores for headphone amps. I use 250 ohm headphones and sometimes the 0404 is a little underpowered. I just haven't had the cash to upgrade to a nicer headphone amp, but I'd like to get a good valve headphone amp at some point just because I like to listen to a lot of classical music and critical listening so having a great headphone amp would be a worthwhile investment (I live in an apartment).

But again what you have should work.

What's your room like? What's the talent like you're working with?

The real issue here is probably the performer and the engineer and not the gear being used. And if you are looking for an upgrade you will see and hear for $1500 I'm gonna be the first to tell you it's probably not going to happen unless you really know your stuff, your talent is flawless, and your room becomes a professional recording environment none of which will be achieved by spending only $1500.

Maybe before you spend anymore money you should simply practice your craft and learn to use what you have. Then if what you have actually works for what you are doing you can just save your $1500. Saving money is always wiser than spending sorry if that's not very slutty of me but I'm 24 and I am speaking from experience and in this economy I'd rather have $1500 in my bank account than wrapped up in a bunch of gear that I don't really need to survive.

I'd check out some plugins for your DAW do a search on the forum there are plenty of cool freebies as well as the usual suspects to purchase.