Looking For More Detail

Adjusting VTA can improve detail.

Islandmandan nailed it. First get a Mint LP protractor. The 9 sig is MUCH better than the regular 9. Then a new cart.

I think replacing the AQ Copperhead with Cardas GR would be a big improvement, no matter what you do elsewhere if the wire can't convey enough detail what you've done won't be heard.

Are there other good IC's or are those the best choice for his system?

The key in analog reproduction is the Phono Stage or Phono section in a preamp. Cartridges show differences of course, but from my opinion I could live with a cheap cart. in combination with a top phono but not the other way.
When you want to change the cartridge I think in the overpriced cartridge market the Lyra Helikon closes the gap between superior detail and musicality for a real good price.
cheers