Country Specific SERP rank checker

I have recently qualified as a SEO professional and am slowly coming to grips with SEO. So any help will really be appreciated

Best country Specific SERP checker for yahoo, bing, google?

                                               I have been checking out  SERP rank checkers that are  country specific and have been getting the most bizarre results from  them.  

When searching normally in google, yahoo, bing altavista ect I obviously have been getting correct results. Luckily the website is ranked on the first page of all major SERPs for specific keywords.

However when I use different SERP rank checkers with say google.co.za (south africa ) set it gives completely differenet results from the search engine results.

I have been using http://www.seoserp.com/web_tools/google_keyword_position_tracker.asp

I have tried others but they seem to be global rankings.

I have also used http://www.serprank.com/ which has given the correct page the website appears in the SERP but not the exact position.

Does anyone know of a reliable SERP rank checker where I can set the country I want to search in for google, bing, altavista and yahoo.

Can anyone suggest a reliable SERP rank checker

an example is when searching in yahoo “conference organiser south africa” it comes up as ranked 1 for south africa but on rank checker it is ranked 11

Need to check it once and then one can give any suggestion!