PPC and wordtracker keywords

I have just finished my free trail with wordtracker and although I believe wordtracker is the de facto choice of tool for keywords I feel that I am still not 100% confident going into a PPC testing phase. This is my 'go, no go' point. I have spent my hours on this project and dont want to get this wrong at this point!

My product is related to the iphone, and is a gadget. There are lots searches(>200 searches per day) for things like 'iphone accessory' which for me is a bit too general and I dont feel that this is highly targeted to my product. There are other keywords such as 'iphone case' which are related although not really targeted! The really targeted keywords such as 'iphone stand' are extremely targeted but only have a very small amount of searches. Something like 4 searches per day.

Can someone please help with a good strategy and give me some advice on this?

This is quite a logical term for the Ad creation and must be explained in short text using effective keywords so that more clicks n impressions may come to your Ad. For targeted keywords there are lots of keywords tools available like google keywords analytics,nichebot classic besides wordtracker.. You may try it n will get your desired keywords...