Here’s an idea for some small ones. As I’ve learned over the last several weeks of committing atrocities on those poor plants, they work better with a 5.8-6 ph using salts (Osmocote). It seems in these small ones, once the plant gets big it sorta defeats the purpose of being a SIP since it out drinks the res’s capacity (.25-.5 gallons) in a 24 hour period. Not good if you also forget to fill one.
I’ll echo the City Picker recommendation, especially if you catch them on sale. But you’re 33% of the way there going the DIY route, just need a void (the lid sitting atop some bricks) and fill tube.