What kind of spark plugs will I need?

Really the tell tale signs of needing spark plugs come much later than 90K. You are due for them. I would also change the plug wires at the same time. As for what kind...I would personally suggest a Bosch plug that has two electrodes. It will provide a better spark. In my Mustang I am running Bosch Fusion plugs which have an iridium center surrounded by platinum, and four electrodes. I also paid $15 a plug for them. If all of this sounds confusing, Go with a standard plug with a platinum core, and you will be fine.