I have a 03 Pilot and love it!! We've driven from SC to IN in the winter time and it has been a great SUV in the snow and slick roads!
The outside seats in the middle row have latch and the middle seat seatbelt is a lap/shoulder combo on mine. I've had infant carseats in all 3 places (did not use latch) with and without bases and they all fit fine. I've had a Britax Marathon on the passenger side with latch and it was fine. I've also had smaller front facers on the sides of the 3rd row but I've found that they and backless boosters fit better on the driver side. It's as if the space is wider there out of the other two seats in that row. The 3rd row does not have latch. I have 2 kids of my own and I baby sit kids from baby to toddler so I've have a lot of kids in my car at one time! lol I've had the Britax on the passenger side 2nd row, infant car seat on driver side 2nd row (without base) and would fold that side down to allow the toddler in the back in/out. It seems that the passenger side of the 2nd row is the widest there.
Most of the carseats I've used have been big and bulky (Britax, Graco infant carrier) which made it hard to get 3 of them in the 2nd row. But I know there are skinny seats out there!
Best thing you can do is go to the dealer with all of the carseats you will be using and install them in the Pilot you are looking at and see what you think!! Play around with different placements to see what feels and works good for you. The salesman will understand and should realize that if you can fit your family in it then that will help seal the sale!!
Happy car shopping!