I'm afraid I can't help because most of these people there are either with their companies or with their entire family. Will you be working in Doha?

Anyway, I think it would be alright for you to get an apartment first, then look for some other expats, who will be coming to Doha(there are lots of people coming in everyday), to share the unit with. It's always better to choose whom you wish to stay with rather than the other way round. Of which, you might be burnt in the initial stage because housing prices here are rocketing sky high.