In general, SW suburbs are going to be most expensive. That's a broad statement, and there are definitely exceptions. In general, it's less expensive on the north end of town than the south end of town.
You will probably want to take your commute into account. Decide how far you want to drive and determine a radius from there. Then start looking for schools and such. If you can't find anything acceptable, then spread your search outward.
Schools in MN are typically well thought of. Most suburban districts are worthy of note. Of course, everyone will have something to love about their home district and something they don't care for. So, it can really be objective.
I know for me, preschools were not something I based where I lived upon. We ended up doing ECFE classes which was more than fine. So I can't give you a lot of help there.
I think if you end up on the SW suburbs, any of the school districts out there are fine. At least nothing where I would say, "Don't even think about going there!"
We also have a lot of charter schools in MN that are quite good. Both my kids attended a Spanish Immersion charter school through grade 6 and now are continuing with an extension program in a local middle school that's part of the public district.
If you really want to look at something to quantify, you can look at School Report Cards on the MN Department of Education website. But I'd look at that with an objective eye. That should not be the only metric by which you measure a school or its district.
As far as getting to WDW. MSP is easy to get to. I'm on the north side of town and it takes me 30-40 minutes to get there, depending on the time of day and how fast I'm speeding

. Even if you are on the south end of town, you may have that long of a drive, depending on how far you are. But the airport is in Bloomington/Richfield on the south end of town.
NWA/Delta, Airtran and Sun Country fly non-stop to MCO. Be prepared to pay higher prices than Detroit though. You rarely get fares (including taxes) for less than $200. Lately, $250-$300+ has been the norm.
Public schools have a fall break in October. Depending on your school district, you'll get 2-3 days off - W-Th-F of Columbus week, typically. A lot of people head to WDW and the airlines know it. So if that's your travel time of choice, book early.
Spring Break varies widely. It can be anywhere from late February to early April. School districts can choose when to have their break.
We are one of 3 stupid states who have a law that says public schools can't start until after Labor Day. That means this year, we don't start until Sept. 8. In our district, our last day of school is June 10. Puke. Your ending day can vary as school districts individually have a set number of student-teacher contact days.