Remember that you only need one visit to your FFL/SOT to pick up the can when your form 4 is approved. I usually mail customers the copy of their form 4 with my portion filled out and let them submit it on their own. They only have to visit me to pick up their cans. It isn't like you have to do lots of trips.
If you're looking for a can that will cycle a .22LR pistol, check out the SWR spectre in addition to the sparrow. The downside for me on the sparrow is the first round pop (FRP). The design sure is nice. You can diminish the FRP with an ablative, but I like running cans dry.
If you'd like to go with a 9mm can for use on a rimfire and 9mm host, I'd recommend SWR's all stainless Octane HD. This can is one of the best on 9mm and is user servicable. You will likely have trouble cycling a rimfire pistol, though. Another option is one of the subgun 9mm cans made by the Bowers group. Tom Bowers is a super nice guy and stands behind his stuff. You can gunk it all up with rimfire crud and send it back to him. He'll clean it out and ship it back to you for a grand total of $20!
Jake (from Ypsi, MI)