Just got these, cheaper than OEM smart ones by a good margin. $55 shipped. Same length (within a fraction of an inch), same ball cup size, very good strength (not hard to open or close, but stays lifted very well).
Signature brand struts, part number SE115P30-1175, sold by Lift Supports Depot.
They took like 5 minutes to install. once you remove the old ones, these just press on, no need to release the clip. open and shut a few times and they are perfect.
instructions to remove old ones: Evilution - Smart Car Encyclopaedia
i just used a flat head screwdriver and pried the thing out till it released.