As far as the western suburbs Garnet Valley is going to have the newest housing. Garnet Valley is a huge growing community made up of swarm of smaller mcmansion developments.Sidewalks? Yes but they only meander around the development. Nice community , fairly new schools,new roads, new town centers etc etc. If newer housing is your priority you are better off in Garnet Valley,Chadds Ford, Westtown,Glen Mills.
Media and Swarthmore are the most town friendly/ walkable but they are older with character rich houses,Swarthmores older housing stock is incredible. Nether Providence, Upper Providence,Rose valley,Rose Tree are beautiful neighborhoods in the Media-Swarthmore area. Older housing stock but very nice areas in your price range. Not sure what the taxes are like in Chicago but keep that in mind. Depending on where you live especially Swarthmore you can pay up to $10,000- $11,000 per year in school taxes for a $500k house.
Aston + Springfield are older middle class towns , the schools are good but you can do better at $400k-$500k.
Walkable communities are Swarthmore,Media, and up on the Main Line-Wayne, Narberth,Ardmore,Wynnewood,Bryn Mawr, Haverford etc etc..
Walkable towns with newer housing stock is tough to come by in this region, its usally one or the other.The town of Wayne might have the best combination of both.
Good luck.
There is a swim club in the Media area Knowlton + Hidden Hollow. 2 pools for the price of 1. They are on an old fruit orchard Linvilla
Linvilla Orchards - your one-stop destination for online fruit basket orders, Pick-Your-Own fresh fruits, gifts and crafts for all seasons, farming fun and education for families, schools, bus and day trips, as well as our famous bakery, farm market,
As far as parks Ridley Creek State Park is in Media. Its an outdoor recreation area 2600 acres. There is a paved bike/jogging only trail, hiking trails, fishing horseback riding etc etc.
Plus Each town usually has its own seperate little park area.
Ridley Creek State Park
Pennsylvania State Parks - Ridley Creek - PA DCNR
Valley Forge National Historic Park
Valley Forge National Historical Park (U.S. National Park Service)