To bring your wife on visit visa.
1. You need NOC letter from your employer.
2. You should have a marriage certificate
3. your wife should have a valid passport
I think no need to show salary here but its better you get your salary here as may be you need to show some bank statement on later stage if you want to get Family visa.
At Al-khor flats are not generally available what is available is Villa,you get furnished villa portion may be around Qr.3200 (1BHK) and if you go for semifurnished or unfurnished with sharing kitchen you may get upto QR 2000 or Qr2500 (1BR/K)

Regards.