not sure if your still looking into them, or not, but you can get a range of thicker needles in the uk here; http://vetshopni.co.uk/shop/pig-products/needles-and-syringes/reusable-stainless-steel-various-sizes.html, most bbq forums seem to be recommending somewhere around 14g, though because of how short that needle is, 16g might be a good compromise there luer lock, and therefore should be compatible with marinade injectors on the market, of which the cheapest i can find in the uk is http://www.keengardener.co.uk/barbecue-accessories/3065-napoleon-deluxe-marinade-injector.html?utm_source=google&utm_medium=base which is £7.93 shipped im trying to find the almost perforated needles you can find on the metal cajun injectors, but no luck so far