Reverse Light Wiring Help

[misterb-fx4]

I have a 98 which uses 3 bulbs in the tail lights (brake/turn/reverse). I bought some new ones that are 2 bulbs.

My plan is the use the brake and turn signal bulbs in the tail lights of course, but use the reverse lights externally.

Can I just cut off the normal connector, so I'm left with +/- wires. Then get some auxiliary lights (like these http://www.walmart.com/ip/Blazer-Rea...Light/15111237), and connect one of these axillary lights on each side?

I just need someone to confirm that the stock wiring/fuse can handle 12v 55w reverse lights. Anybody know which color wire is positive and negative? If these lights are too powerful, what should I look for?

Thanks in advance!