I think you should open up a vote thread so you can share some ideas and designs, and people would tell you whats better, so you will know what people likes and more likely to buy and whats not.
Also my suggestion is creating a limited amount of sets that cointains the same design of coin in 5-6 different metals I think people here are going to buy them instantly.
You should also consider minting coins that has private key minted on them (not an hologram,the coin it self has a design of a private key) which can be really cool but I assume that creating those can cost a lot of money.
I will likely take your advice on that. Though, I'll probably just produce a few things even without a poll just because at the very least I'd want one. With the exception of my idea for the Bitcoin pocket change concept, each piece I make will be hand numbered, I'll decide ahead of time on total mintage based on popularity. Typically what mints like Perth do, is they decide a maximum mintage of a certain coin + a deadline, and they will not exceed that mintage. Lack or orders or interest could cause the total produced to be under the maximum mintage, so if you look at the Lunar series silver/gold coins for example, of a maximum of 100,000 some years only 30,000 were minted. More difficult and exotic metals will probably have fewer produced than the universally popular copper, silver, and occasionally gold, but if there is enough demand, maybe not.
Pretty much the decisions that I make will decide if they will be individual pieces worth their value as art pieces, or if they will be funded before shipping and have a secondary market. I'm all for having a secondary market, but I'm not a huge fan of handling other people's private keys.
Should I find a solution that allows it, I would indeed like to have private keys directly on the coins. There are a few reasons not to do that, but I may be able to come up with a solution. I had a 2013 1 BTC Silver/Gold Cas coin go through the washing machine, and that sucked pretty bad. I'm curious to what kind of resolution I could get a cast QR code onto a coin. Thats something I'll have to try to find out.