I think you're right about the fish oil, the brand I take at the moment seems to have fairly low levels of EHA and DHA, I take four capsules a day each with a breakdown as follows:
Omega 3 Fish Oil 1000mg
Eicosapentaenoic Acid (EPA) 180mg
Docosahexaenoic Acid (DHA) 120mg
Also, have ordered the same brand of Vit D you've recommended, tracked it down in the UK, should arrive tomorrow.