So two years ago I bought a Entry level road bike a CADD 8 with 105. I rode it recreationally for the first year and more serious the second. Now that the season is starting and I want to train for my first Century and maybe a Cat 5 Crit. So far the bike is 100% stock. I have been investing my money in clothing and accessories like Glasses, apparel and small accessories no major parts.

I'm looking to upgrade the bike and ride it for another two years or so. However I was wondering if I'm taking the right upgrade path. My dream bike is a Cervelo S5 but I think I still have not out ridden the bike that I own now yet and dont really want to get dropped on an S5 sorta speak, ego bruising.

Looking to upgrade the following

Saddle: probably Specialized at least 300
Wheels: Fulcrum Racing Zeros: 2 way fit so that I can move into road tubeless as I get more comfortable with the tech or another set of wheels
Component Set: will stay the same till I get a new bike

What say you?, are the wheels over kills for the bike ?