My biggest piece of advice is to avoid any academic based preschools.
This would be mine as well.
Also, we didn't have great experiences with skipping ahead in classrooms before pre-k age. There's so much social and emotional stuff going on before 4 years old. I regret allowing DS's preschool to skip him ahead by a year when he was 2.5. My daughter will stay with her same aged peers until 4.
My son was ready for academics at 4 and we did find a great "transitional K" with gifted peers, just by chance, and that year of pre-k may end up being our favorite year of school ever.
We're only on 1st grade though!