To emulate the LMB's "enhance" using a different EQ, cut a narrow notch at 2 KHz, and boost a spike at around 4.5 KHz. See the graph here for more detail: http://www.ovnilab.com/reviews/bosslm2b.shtml
The deal with the hiss is twofold: first, boosting everything above 4.5 KHz will always boost any noise that's already in your chain. So you have to eliminate noise from your bass or any other pedals. Second, the gain stage in the LMB is not the greatest, so you will get better results using an EQ that is inherently less noisy.
I'd suggest the Empress Parametric EQ might be the most practical replacement option.