Questions for adding amp-sub combo to Bose

[kiroro]

I have a MS3 GT with Bose and thinking about getting a 12" sub and mono-amp for more bass. I plan to keep the stock HU and speakers.

Mono-amp: Alpine MRP-M500, 300w@4 ohms, 500w@2 ohms
http://www.sonicelectronix.com/item_12018_Alpine+MRP-M500.html

Sub and enclosure:

1. Kicker 12" CompVR Sub + Box + Wire Combo, 400w, Dual 4 ohms, $149 shipped.
http://www.sonicelectronix.com/item_5386_Kicker+12-+CompVR+Sub+++Box+++Wire+Combo.html

2. Alpine SWR-1242D (Type-R) + Scosche SEV12, 500w, Dual 4 ohms, $165 shipped.
http://www.dealercostcaraudio.com/swr-1242d.aspx
http://www.dealercostcaraudio.com/sev12.aspx

First question: Which enclosed sub is a better fit?
Since both subs have dual 4 ohms, I guess they could be parelleled so the amp would output 500w at 2 ohms.

I have read some previous posts and understood that I could tap the pre-amp signal since I have the bose. So I plan to hook the speak wires directly to the Alpine amp since it has the high level inputs.

Second quetion: What else do i need to buy to install the amp and sub? cables? wire kits? ( sorry i'm a car audio noob)

Thanks!