Square Marie-Curie.....several choices and not easy either.
a) live outside Brussels in a Dutch speaking area such as St Pieters Leeuw or Halle and take the de Lijn bus to work or drive - but I think your wife may not like that choice at it will be a very "provincial" life.
b) live nearby and walk to work or take a short bus/tram/metro ride, in the commune of Anderlecht (1070). Housing is a bit cheaper over the west side, you do have some pretty spots like the ponds around Marius Renard near your work and near the 81 tram route, you also have Westland shopping centre, Cora supermarket. But you would really need to choose very very carefully in Anderlecht because some areas are a bit seedy, schools are packed out there, due to the terrific rise in birth rate, especially in the large Moroccan population, schools do not perform so well over there, few exceptions at secondary such as Athenée Bracops Lambert and Institut des Soeurs de Notre Dame, the latter has a maternelle and primaire too. Both these 2 renowned Anderlecht secondaires are near St Guido no 5 metro / no 81 tram stop. I know it's a bit looking ahead, but a good secondaire usually has good maternelles / primaires nearby, so do take this into account when choosing an area. If I were choosing Anderlecht, I'd try and find somewhere from work along the 81 tram or 5 metro routes.
c) live in the centre of Brussels, say right in the centre within the inner ring, that would be Bruxelles 1000, or in St Gilles (1060) or Ixelles (1050) where you could catch the 81 tram or metro line 5, depending on exact area. You will find it a bit more expensive to much more expensive than Anderlecht but still within your budget, mainly apartments in this area. The advantages are that everything is on your doorstep, schooling is not good however in St Gilles, a few excellent schools in Bruxelles 1000 and Ixelles, but hard to get in to. From the very centre of Bruxelles out to Ceria no 5 metro stop (nearest metro stop to work) would be 20 minutes. From Flagey area of Ixelles to Marius Renard 39 tram stop (nearest tram stop to work) would be 40 minutes, from centre of St Gilles on 39 tram would be 30 minutes.
d) live on the east side of Brussels along the no 5 metro line. This will be again a bit more expensive than Anderlecht, but more houses instead of apartments, more open spaces, more choice of schools, still everything on your door step. Look at the no 5 metro line, it passes through Etterbeek (1040) and Auderghem (1160) and very near north area (Place Keym) of Watermael-Boitsfort (1170). You could still get a 3 bed house there for €1200. It would be 35 minutes from the end of line 5 at Herman-Debroux in Auderghem to Ceria metro in Anderlecht, closer into city centre it would be 30 minutes from Thieffry metro stop in Etterbeek. So if you chose a house near metro line 5 further away from work, you could still get to work quicker by metro than if you chose somewhere nearer to work such as Flagey area of Ixelles!
Here is a link to maternelles / primaires in Brussels, nearly all schools appear on that map. If you chose option d), you have the greatest choice of good local schools, but you have the biggest housing cost, but then again you also have the biggest choice of housing.