So you are in Mississippi or West Virginia? All other states have at least a religious exemption, as far as I know. (Can you say that you religiously "believe" in not giving vaccines that concern you? Sounds applicable to me.) Your baby's breastmilk is a great vaccine, but you may want to choose some vaccinations as he gets older. If you are concerned about the pertussis "outbreaks," then you'd want the vaccination as you hear about them, as that vaccine doesn't last very long. An old vaccine might not protect.
It's best to provide good nutrition, maybe a multi-vitamin, and add some good anti-oxidants (like vitamin C and grapeseed extract) before and just after a child is vaccinated, and then have them rest well. Treat them as if they are a little bit ill, because they are. That aluminum adjuvant is a concern to me. Yes, I guess spacing those out would be better. Some parents are choosing to give separate vaccines rather than the mulitple cocktails, but if this means multiple exposures to aluminum adjuvant, I wouldn't go for that.
When looking for an alternate vaccination schedule, I will defer to Dr. Sears' schedule. They know what they're doing there.
Just to clear up a common misconception, hoping others see this, "exclusively breastfed" (the term you used) means nothing else is given at all but breastmilk. Outside of a little water, anything else given, be it formula or baby food, changes the physical health picture. For this reason, the distinction is made between a child who is exclusively breastfed, meaning nothing at all but breastmilk, and one who is receiving solid foods or other milks or formula along with breastmilk. Just clearing up the definition of the term.