Short-term schooling in Brussels

Hi,
My husband has an offer to work in Vilvoorde for three months starting in February. We have a second-grader and a Kindergartener in the U.S., and I'm wondering if anyone has advice for schooling for such a short period. If we were staying much longer, we'd love to have them learning French in the local schools, but I'm not sure it's a good idea to go through all the frustration involved in those first few months without (presumably) the reward. I like the idea of a French-English Montessori (my kids go to Montessori/progressive ed schools here in the US), so I was excited when the European Montessori school said they could accommodate a short stay. However, the only comment I've seen on this forum about that particular school was extremely negative.
Anyway, I'd love general comments on what type of education to seek (int'l school/local/montessori/tutor?) as well as thoughts on which specific schools to approach.
Also, we think we like the neighborhood of Stockel, but aren't committed to any specific location (as long as the commute to Vilvoorde isn't awful).
Thanks!
Sheila