capacitor value substitution
You must be looking in the wrong place. Go to digikey.com and enter the appropriate parametric search, and you'll find all the components you want:
http://www.digikey.com/product-search/en/capacitors/ceramic-capacitors/131083?k=capacitor

Substituting capacitors used for bypassing can work just fine; typically more is better in those cases (as long as ESR and voltage rating is sufficient.) Substituting capacitors used as part of a tuned filter is much less straightforward. Thus, to answer your question, we need to know the role of each of those capacitors.