I just bought my first guitar couple days ago and someone said that the factory strings should be replaced with good ones. I tried to buy some expensive strings at eBay but backed out at the last minute because there were so many "sizes" and dynamics involved that I didn't know which ones to buy? I have an Ibanez acoustic. I don't think that I need the top of the line because I am brand new to all this but I would like a recommendation for maybe the next best to the top? Many thanks in advance.