So, for fun, I've been re-calculating the relative infrequencies of all the poker hands, then all the poker hands with five suits (which includes a new type of hand, a "flash," which has one card of every suit), poker hands with six cards (which allows for three pairs, two threes-of-a-kind, and a four-of-a-kind plus a pair), etc. These various permutations of the standard rules all have their own effects on the table of hand-rankings. I even computed odds for a hypothetical 51-card deck of three suits and 17 cards per suit. The book I mentioned above mused that it would be really great to have a 60-card deck (either 4 suits with 15 cards each or 5 suits with 12 cards each), because 60 has so many divisors, so I did odds for those as well.
I have various ideas for playing card decks, and the U.S. Playing Card Company (maker of Bicycle and Bee cards, among others) offers some fine custom printing. There are five-suit decks out there, but not of the quality you'd see in a Bicycle deck. You can't custom-print one through the USPCC because their deck size is 56 cards. But what if I printed a deck of four copies of the same "fifth" suit and combined those with four ordinary four-suit decks (with the same back)? That would be a fine set of cards indeed! Now all I need is about 400 people who'd want to buy one (100 decks is about the smallest I can get even through the USPCC's "third party" printer). There's also an ordinary 4-suit deck I'm working on with custom pips; more on that if anything ever comes of it.
These are good projects, I would think, for Kickstarter, but even there I despair of getting needed support. Just don't feel like I could muster enough marketing.