Coming from the "Learned The Hard Way" school and having tried assorted "suck it and see" cams, I agree with John. The D cam will give a significant boost in power without turning the engine into a cranky b**tard. Naturally, if you use the extra power a lot, you should expect the fuel consumption to take a bit of a dive. As John said, definitely replace the followers with new ones. Worn followers will wreck a new cam very quickly. Having the old ones re-radiused by a machine shop isn't worth the effort or money. New ones are cheap enough.

As for timing gears, I'm a fan of all-steel gears. But I tend to rev the rings out my engines, and steel means spending more money of course. A fibre cam gear is fine for normal use. When it lets go however it can do so with little or no warning and you'll be going nowhere without a new one or a tow. It'll deposit a load of crud in the oil pan too. No such worries with steel.
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Steve.