I sew on an old mechanical machine. Singer is not good unless it is an old machine (pre-1970). The old ones never quit.

Mis-Cat is spot on about the type of stitches--straight and zig-zag with built in button hole is all you need. I do have an overlock machine (not in Qatar) and I found it good for some things, but frustrating for others. Those machines tend to be harder to thread, and the knife makes it so you can't correct mistakes as easily.

I'm not sure about the best brands in Qatar, but in the US, I'd stick to Bernina, Elna, and Janome.