Well you could always take them out of the box and look... They should have a sticker on the back of the magnet that will tell you how many voice coils at what resistance, plus RMS power handling capabilities.
As mentioned, you really shouldn't guess at this stuff unless you like frying things.
EDIT - Also, you CAN use RCA splitters for your signal and you CAN just daisy chain the remote wire from amp to amp, but I wouldn't really recommend either. I run multiple amps and I wired up a relay to handle the remote wire, this way I'm not attempting to draw too much power from the head unit. If you pop the internal pico fuse your head unit has for its remote wire, you're screwed. Regarding the RCA splitters, you're degrading signal strength when you split them. Which will result in gains having to be turned up higher, and possibly clarity issues. Most decent head units these days have two or three sets of RCA pre-outs, you'd be a lot better off running a dedicated set of RCAs for each stage (front, rear, subs) directly from the head unit. If your head unit doesn't have these capabilities, personally I'd be thinking about upgrading that before you go any further.