Perth Mint is a government guaranteed metals refiner and one of the worlds major producers. That's much safer than any ETF, which, like any ETF is subject to the whims of the market, and in drastic market conditions ETF's can become illiquid very quickly. If the market shut down, you can't sell your ETF's, and that is happening a lot lately. And in this "physical is all that matters" market, Perth Mint unallocated (still physical based on raw material stock) has got to be safer.
There is a heap of CFD providers. Try pick one that has an office in Australia with all licenses and a support phone number in Australia. There isn't any free CFD providers. The way they make their money is the tom-next rate marginal interest and the spreads. I wouldn't cheap out on a CFD broker. Unallocated is a single company saying they are accounting your money to some physical and maybe a paper hedge portion too (you have to read the fine print). Its tied to that company staying afloat. I doubt you will get anything beyond an email receipt as proof and I'm not sure how much they charge to hold it for you. Most companies see their unallocated offering as their customers paying for their held bullion stock (for sale) at any one time. and they charge you for it... Buying ETPMAG stocks is like buying a company stocks. You have the ASX regulating everything the ETF does, knows the people running, have reporting requirements and be open with everything they do including a register of stock owners, like any publicly listed company. ETF usually around 0.5% a year fee and the silver ETFs usually all buy into the huge LBMA silver vaults in London. If I was to choose between these for long term hold I would go the ASX ETPMAG ETF over any single company's unallocated.