Anyone know anything about disc brakes?

Definitely the L's but resin or metal?

12 Y8N398010 Resin Pad (K02S) & Spring A
13 Y8N398020 Metal Pad (K04S) & Spring A
14 Y8N398030 Resin Pad (L02A) w/Fin & Spring A
15 Y8N398040 Metal Pad (L04C) w/Fin & Spring

http://www.madison.co.uk/products/cycling/transmission-braking-components/brake-pads/l04c-disc-brake-pads-alloy-backed-with-cooling-fins-metal-sintered/

"The metal pad (clearly etched on the pad’s backing plate) material is sintered to a steel backing plate, which essentially means it’s applied in layers and welded on. The resin version is bonded to an aluminum backing plate. The resin pad is a softer material that is designed to provide more modulation and noise control at the cost of raw power and fade resistance. The metal pad uses a much higher percentage of metal in the compound, resulting in a more rigid construction. This is designed to increase power, fade resistance and durability at the cost of noise and modulation. It also increases the weight about a third of an ounce per pair. The resin pads retail for around $30, and the?metal pads retail for roughly $40."

"We knew we would like both pads, but we expected the raw power of the metal pads to win out. To our surprise, for most circumstances we tested in, we preferred the resin."

http://mbaction.com/product-tests/product-test-shimano-metal-vs-resin-brake-pad-compounds

Thinking I could put metal on the rear for its durability and power and leave resin pads on the front for modulation (so I don't throw myself on the ground panic braking)?

http://www.pinkbike.com/news/brake-pad-information-2009.html

In my opinion you should run metallic pads if:
-You are heavy
-You ride downhill
-The conditions are wet, muddy, etc.

and run resin pads if:
-you are light
-Conditions are dry
-You like lots of initial grab
-Your riding is less hard on brakes i.e. dirt jump/street, XC, etc