your best bet is either a cap and rotor manufactured ny summit for $130 and an oem optical spark sensor, or the entire distributor from GM performance that you can get from thunderracing. The gm performance parts one is a good deal it already has the sensor with it. I would personally go with a stock coil because aftermarket idnition parts tend to mess up the opti. If you are considering doing plug wires too do them at the same time, and if you decide on wires like accel 8 mm they are great the only problem is fouting them behind the powersteering pump like the factory setup because they wont fit into the stock clips, which makes it a chore.
AS far as installing the rest of the system you will first need to take out your intake tube and you cooling fans. Then the harmonic balancer, but you bant use a normalll puller on the ballancer because of the setup. The inner part off the pulley stays on the crank while the outter part comes off. Then you need to take the water pump off. This gets alittle messy because the bolts go through the block and coolant spits oput when you take them out. Make sure you thread seal them before you put them back in. The rest is pretty eady, Its litterally imposible to mess up the timing, it will only fit on the spline one way. You will need to track down a T-8 torxe socket to get off the cap and rotor. Then you just put it all back in