Hi John!
I would certainly give those restaurants a try. Have a back up quick counter service location in mind just in case, and continue to check back for any openings for the reservations you'd like meanwhile, but I think trying for those restaurants you'd like to dine at without reservations is worth a try.
With two guests, it's possible for space to open up. I've had a group of about 9 guests (in semi-peak season) walk up and be seated at some restaurants (even those with character dining) with anywhere from a 15-30 minute wait.
Also, you might be surprised by the number of last minute cancellations that occur the same day or evening prior, so I would keep the dining reservations phone number (407-WDW-DINE) on hand and try for reservations even on the same day if there is an absolute must on your wish list.
Best of luck and pixie dust for those dining seatings you'd like! Have a magical vacation!