Tons of Tech Questions!

You can get away with wireing up 1 VC on each sub and paralell them to get a 2 ohm load, i have done it many times, and i have contacted alpine about it, its safe to do so. Whell, not as safe as splittin the power over the 2 VC's, but i have never ever had a problem.

That amp will definately not go to 1 ohm, 1.5 ohm is the most iv gotten one down to without it shutting down from over current.  At 1 ohm to much power is drawn through the amp and the amp says No, and shuts down.

Also about your question about the 9835, , i loved it, best deck iv ever had, , almost to complicated, , but after you take the 2 hours to set it up, its very easy to use.  I no longer have it, , i sold it to a customer who offered me $300 more than what i paid for it, so im back to factory deck, and a LOC.  Im kinda glad i sold it, , cuz my elctrical system went on the fritz, my ignition wires turn to negative when the ignition is off, i can't belive my truck hasn't melted yet.

I'll get a new one once i get this problem fixed.

This is what I pulled up from JL's Tutorial on their site:

A common misconception with regard to dual voice coil speakers is the assumption that nothing changes if you power only one of the voice coils. With only one coil hooked up, a dual voice coil speaker will suffer a loss in reference efficiency of about 3dB (only half the coil windings are being energized) as well as a significant shift in its Thiele/Small parameters. This renders any enclosure calculations inaccurate unless you remeasure the speakers parameters with only one coil hooked up. Failure to account for the different parameters of a dual voice coil speaker with only one coil powered can result in very poor performance.

I guess I will try the 4 ohm load, if it doesnt work out for me I may go about trying this one coil method.......

The RMS rating of a speaker indicates the maximum continuous power level that can be used safely.  Any RMS value up to the rating is OK to use.

Wire your system properly for 4 ohms, setup your amplifier and head unit properly, and then see what kind of sound you get before you start worrying about making more changes or modifications.