I wired 4 sets of remote speaker pairs with pairs of 14/2 (12/2 on the long runs). Each had a volume control. I found it more convenient to just buy one wire on a big spool of two conductor (single pair) and just pull two cables to from wall plate to attic to volume control for each speaker. Meant less inventory and waste. A little tough pulling down the four cables required for the volume control (two in, two out) but it is doable. An electricians snake or tape is ideal for this part of the job.
I recommend the gray jacketed "sound/security" wire that I got at Home Depot. It is "riser rated" which is what you should get for wall and attic wiring. It has red and black insulation on each wire for easy polarization. I don't recommend using the transparent insulation or zip apart speaker wire commonly found, it is harder to pull through the holes, etc.
If you do get 4 conductor wire, make sure it is intended for speakers and bundled as two twisted pairs, not just a bundle of four, and wire each twisted pair as a single channel.
Be careful not to have long runs of speaker wire parallel to power wiring in your attic.
Since you will need a lot of wall plates at your amp for your five speakers, you might go beyond the 4 binding post plates. I found 8 binding post plates that allowed me two pairs of speakers per plate. There is also a double wide one that has 12, so that can handle 3 speakers. One of each of these would give you your five and you would only have two boxes for all five remote pairs. Use the low voltage "boxes" that are open for mounting the plates.
If you have a soldering iron, I recommend stripping and tinning each wire, that way the strands don't get bunched up and have a chance of some shorting to adjacent posts. You'll need a high wattage iron for the #12 wire, though unless you have a very long run, 12 is probably over kill (and a pain to work with).
