A #10 blade is a 1.5mm blade. It's a pretty standard blade size, and very often when you order a set of clippers a #10 will be included. The #7 will leave the hair a bit too long for heads ears and faces, and the blade teeth are further apart so there is more risk of catching a lip or eyelid.
The blades for a Moser will not fit an Oster, Moser has it's own style of blade. You want to look for clippers and blades that say "A 5 compatible". Oster, Andis, Wahl, and Laube all make clippers that are compatible with A5 blades. While Oster has a clipper that is called the A5, it's also a type of blade and attachment on the clippers so you can use a blade marked A5 on any type of clipper that says A5 compatible. For example, if you have an Oster A5 clipper, you can use A5 type blades made by Wahl or Andis, or any other manufacturer, as well as Oster blades.
There's a bit of confusion with the name "Moser", as I guess there is a Moser, and then there is one called the Wahl Moser Arco. The Wahl Moser Arco has one blade, adjustable to 5 lengths (all very short--#9,#10,#15,#30 and #40) and is cordless, it's a great clipper if all you are doing is faces and ears. If you are going to do the body I would recommend you go with the A5 types
Any online dealer that ships internationally should be able to supply the right blades, and they will fit an A5 compatible clipper, regardless of where you buy the clipper.
Hope this helps!
