Disney had vacation planners just like you in mind when they created this
calendar that suggests great times to visit based on the three specific criteria you mentioned. As of right now, only January 2009 has been updated. You'll see that the first full week of January, as well as the one that follows it, are highlighted, indicating that those are ideal weeks to visit. I would suggest bookmarking that page and continuing to check back for updates.
Historically speaking, the following times of the year have also been nice times to visit, based on value, crowds, and weather:
- all of January (with the exception of the first couple of days of the month right around New Years Day)
- the first two weeks of February
- the latter part of August and all of September
- early December
Considering the fact that you want to travel between January and June, I would recommend that you plan a visit for early February. That will give you the most time to arrange dining and resort reservations, while still staying within your guidelines.
Hope that helps!