Shoe trees - I've seen spring loaded, full bodied wood trees at the shoe repair shops in Vivo and Plaza Singapure. Both also sell at about $60/pair if I remember right. I've also seen some less full versions in Muji for $45/pair. As mentioned above, if you can get friends together to order at least 5 pairs, buying online from Bexley is a great option.
Cream/Wax/Conditioner - I get creams from shoe repair shops. The MasterFix chain should have Collonil cream which is good. Dasco is a good brand overseas, have seen this in Pedro shops, but I haven't tried it myself. For wax, you can get Kiwi which is available anywhere.
I get my Saphir stuff from chelseashoerepair on ebay. Good prices and reasonable shipping. Edetal also has Saphir, but I'm not sure how much he charges.