One Amp or Two?

I'm looking to upgrade my amplifier.   I'm currently running an Alpine MRV-F540 5 channel amp.   At 12 volts, it's rated at 30W RMS x 4 for the front and rear channels and 150W x 1 for the sub channel.  At 14.5 volts, it's rated at 50W RMS x 4 and 200W RMS x 1. 

I have an Eclipse CD8443 with 8v preouts, so I need amps with input sensitivities of 8v (or close to it).  I'm running JL Audio VR650-CSi components in the front and JL Audio VR650-CSx coaxials in the rear deck.  Both sets of speakers are rated at 60W RMS.   I'm also running a JL Audio 10W3V2 sub which is rated at 250W RMS.

Right now, I'm leaning towards the JL Audio 500/5 which has a regulated power supply and is rated at 100W RMS x 2 for the front, 25W RMS x 2 for the rear, and 250W RMS x 1 for the sub channel. 

Would I be better off looking at two seperate amps instead?  For the same money, I could get the JL Audio 300/4 (75W RMS x 4) and the JL Audio 250/1 (250W RMS x 1).

What I like about the 500/5 is the distribution of power between channels, the convenience of running a single amp, and the added flexibility the 100W per channel gives me if I decide to upgrade my components at some point in the future.

On the other hand, the 300/4 and 250/1 setup is a better match for what I'm currently running and gives me more flexibility to upgrade if I decide I want more power for the sub or the components in the future.

Right now, I'm not looking to run more than 500 to 600 total watts RMS.  I have a 2004 Honda Civic sedan and I think the alternator puts out between 60 and 70 amps.  I don't want to get into a situation where I need to upgrade the electrical system.

If I go with two seperate amps, I can also look at Eclipse and a few other brands, but I really like the "what you see is what you get" nature of the JL Audio amps since they produce the same power between 11.5 and 14.5 volts and into 1.5 to 4 ohms.

Any advice, thoughts, or opinions?

I hadn't even thought of the impact the regulated power source would have on current draw.    I was thinking that since my alternator could handle the Alpine MRV-F450 without any problem that it could handle the JL Audio 500/5 as well.

However, the MRV-F450 has an unregulated power supply, and what I thought was a total RMS of 400W (rated at 14.4 volts) is probably a lot closer to a total RMS of 270W (rated at 12 volts).

I've actually got my system sounding very good (at least to me) with the changes I've made over the past week, so maybe I should just stick with what I have for now, even if I am a little underpowered.