Naija Town Square - A Forum For Nigerians At Home and Diaspora

I am interested in recommendations for link building and also SEO.  I have dealt with a couple organizations recently and have been let down.  Can someone know any recommendations for respected businesses?  The one I had been recently looking at is called DiamondLinks.net, they seem to be a complete link building company.  Right now they appear to be the perfect but I needed to check to see if somebody wanted to offer input.