Welcome to the forum. To find a list of reputable sellers, go to the to left of this page, click browse, then forum. Scroll a long way down until you find watches, clothing and accessories. Here you will find trusted dealers. Also at the top right of any page, type Seamaster 300 into the search box and read up on the subject. To the best of my knowledge there isn't an outstanding replica of that model, but it depends what you can live with. I'm happy enough with mine faults and all.