It comes down to budget and features. I have the UL combo from Emotiva and love it. I too am looking forward to the LMC-2 and MMC-2 because of the added features. Something to keep in mind is Emotiva's upgrade options. 40% discount on upgrades to new processors, yum!
Note: Many mid-fi receivers can be just as useful as a seperate pre/pro working as a preamp. They often have more features per dollar even if they didn't have the amplifier built in. Combine a receiver like the Onkyo TX-SR705, the Yamaha RX-V661, or any similarly priced late model receiver from Pioneer Elite, Denon, or Harman Kardon (there are other options as well), with an Emotiva amplifier like the LPA-1.
If you can wait for the LMC-2, which I believe will have HDMI 1.3 built in with the appropriate decoding for HD audio formats, then go for it. But if you can't wait and don't foresee changing much in the next couple years get a receiver that has the HDMI features you need or plan to use in the future by getting a receiver and possibly adding an amplifier down the line.
The Onkyo TX-SR805 presents a pretty outstanding value and would no doubt make the Rockets perform quite well. It has a lot of power for a receiver in this budget bracket, certainly more than any competitor is offering in terms of receivers at this moment. Will the TX-SR805 contend with the LPA-1 amplifier in terms of power?, most likely not. Will the Rockets sound better connected to a more powerful amplifier?, possibly. How much difference a seperate amplifier makes largely depends on your listening habits.
I have no doubt that the TX-SR805 could push the Rockets to levels of output that would make you uncomfortable without sounding very strained. The real world issue that comes into play is dynamics. The receiver isn't going to be able to have the same dynamic impact that the LPA-1 amplifier can deliver. The receiver may run out of headroom, and you may not notice it is doing this until you upgrade to a power amplifier. You may not notice it if you don't listen to music or watch movies at high levels of output.
I think that about covers it.
