Looking to byamp 4699b speakers

Sup All
I recently purchashed a set of 4699b speakers along with an jbl mpc-600 amp and have a few questions.

1. I would eventually like to bi-amp them. The second amp I am looking at is the Mackie 1400i rated at 500 + 500 watts @ 4 ohms stereo, 300 + 300 watts @ 8 ohms stereo. On the back of the speakers there are three 1/4" plug ins for the speakers. One says 4 ohms LF, one says biamp 8 ohms and the other says triamp. So I would assume that the Mackie would be running in 8 ohms in the biamp mode and that th mpc-600 would be running the woofer at 4 ohms. Would this be a nice combination for a biamping these speakers?

2. The mpc-600 shows that it could draw up to 21 amps. I plan on running 2 seperate 20 amp lines to run the amps. Would this suffice? I know that it could draw up to 21 amps but seriously do not think that it will ever get there. I will be running a #10 wire no matter what. Am I seeing that correctly in the specs that it could draw up to 21 amps?

3. I know this may sound stupid but the speakers are about 4 inches to tall where I would like them to go. They will not hit anything but will block whats behind them by about 4 inches. So with this in mind would it be safe to lay them on there side. I will most likely leave them up.

4. I bought some 1/4" connections that I plan on hooking to some #12 speaker wire. They are unballanced connections. For the time being I would like to use these for simplicity sake. Any problems there?

I can not find an owners manual for them except what I have linked to. I am sure there will be more questions to come. Thanks in advance for the help.

hook em up to a set of speakers and put a meter on em.If you use a clamp meter make sure that you isolate the hot wire to get a reading.I use an old extension with the outer insulation stripped.start off at low volume and increase gradually.I would be surprised if you drew that kind of amperage in normal listening conditions................gotta start reading the dates on these things