i totally agree with flying touareg cos the job opportunities are very bright right now.
i dont think an instructors rating will give you any edge at all in nigeria unless of course you want to 'instruct' and the only place to instruct is zaria which has one of the worst salaries in nigerian aviation,so as far as am concerned its a waste of money
now doing a 737 200 0r3 00 type rating at the end of your cpl if you have the cash to spare will definetly land you a job in seconds
american training is cheap(if you can survive visa hassles and tsa)
if cash is not a constraint i suggest you train in the uk,if it is then us or sa are your best bet
salaries? expect somewhere b/w 200-450k mthly depending on the co