I would suggest full body for overall strength and conditioning, alternating with plyometrics for explosion off the line. Also, quickness and agility, like running through tires or laid out rope courses, out and backs, cuts and spins without falling down, etc..
As for what position, it is based on your size. LBs are usually pretty big dudes, between 6'2 to 6'5, 240-275 pounds. DEs make plenty of big hits, usually closer to the line of scrimage. LBs are all over the place, and speed counts a lot for them. What is your current height and weight?
Mt Snow, VT - May 5, 2012 - Completed!
...i remain, he who remains to be...