Like I said in another thread, I'd quickly skip over the cakes.
Using rye you have a much easier time reinoculating.
For instance, you inoculate 10 quart jars with your one syringe. Once all 10 are fully colonized, you can use 6 to make casings and than use the other 4 jars to inoculate up to 40 jars.
If you want to even do it slow, which is what I'd suggest, especially since pressure cooking 40 jars would take a LONG time (around 2 hours PCing and 6 hours cooling), you can just reinoculate with one jar and have a constant cycle of 9 jars worth every 2-3 weeks flushing. Plus, casing out a quart jar into a pan with casing layers, you'd yield MUCH higher. With cakes, it's kind of hit or miss. Sometimes you'll get great yields, but others, not so much.
Now with casings, the smallest yield you'll get on an okay casing, is as much as some of the higher yields on cakes. Granted, there are some people that grow beautiful cakes, it would be easier to case honestly.
If you're just doing for personal use, you can just grow cakes, but even than, you wouldn't be able to really trip often, or with a lot of friends even.
Seriously, look into Rye grain substrate into casing layers, it is on shroomery too, so it should be easy to find.