there are a lot of choices for furniture, for one there is IKEA, I do not know if you are familiar with the brand, but it is very popular in Europe, it is not expensive but of course it is not the best quality, but it will last you at least for 2 years. Check it out www.ikea.com. Now if you prefer something more traditional or chinese style, there is a huge shopping plaza called Ap Lei Chau, it is off the island side by Aberdeen, it has 27 floors of furniture shops, and also some clothing outlets and some kids stores.
I loked up Bel-Air, and I found Bel-Air on the Peak, it is in Wah Fu on the other side of the island, if that is the place you are going to be, it looks a bit remote to me, there is no MTR nearby, you may heve to resort to bus or taxi to go anywhere. But maybe there is someone else here on the forum that knows the area.
I hope this helps a bit, if you wish you can also send me a PM, and I would be glad to answer any questions you and your wife have.