I also had to change my 02 sensors soon after running the Seafoam, but I figured since I was between 85k and 100k miles, I would need to do so anyhow.
It's recommended you do an oil change real soon by everyone who has run Seafoam, and I would also do plugs. However, you should consider coils and o2 sensors if your miles are on the higher side and you have not already done so. If not, you may start having rough idle and cold start issues too. I only say MAY have these. I began having these after the Seafoam, as well as some acceleration hesitation, but after doing those maintenance items, the car is now running 20k miles PERFECT. Smooth as the day I bought it.