You can probably do a better job by collecting the information from each school for the cost of attending and then comparing public to private.
The thing to remember is there are many hidden factors that should not be overlooked when making this kind of decision and if youe children are old enough to understand, make them part of the process, It's important to listen to their feelinga as well.
I wish I knew of a website that could detail this for you, but no luck. This is a question that a lot of people have, especially when choosing between Oak Park/River Forest and the Proviso Township School District.
Forest Park has district 91 with several elementary schools and Proviso Township High School School District. Proviso Township recently opened PMSA (Proviso Math and Science Academy), which by most accounts is one of the best performing high schools. As far as educational opportunity goes, Forest Park doesn't have a poor school district, just not as established as Oak Park's.
Oak Park (District 97) also is a similarly good elementary school district. Oak Park/River Forest High School is a very well established institution with an excellent reputation. This is perhaps the most compelling reason to choose Oak Park as superior in the educational category.
As far as cost goes, Oak Park is a large suburb with a wide mix of housing types, from small bungalows to large estates. Buying in Oak Park can be very affordable in this market. Recent closings for single family homes are abundant in the $250k-$350k range and go as low as $150k and as high as $910k (and has been known to go into the 3-4MIL range, depending on property), depending on condition and location. Taxes almost uniformly begin around $5000/year, increasing as property value increases. Forest Park, by comparison, is a much smaller town, with a more uniform housing stock. You can typically expect to pay $200-$270k for an average home, and taxes are usually a bit lower ($3500 average, in that range).
There is an abundance of Private Schools in the area. Expect to pay $5000+ for a private school (most are +++!).
Either way, they're both great towns and I think it's very hard to go wrong with either option. You can check out the web references below in case you haven't visited the various district's sites yet. If you aren't working with an agent, you can feel free to contact me for assistance.
Best of Luck and always willing to be of service!