I've seen an article on a guy that stroked it to 2.2, don't remember who did it though. I also read another article based on JWT's findings after ripping the QR25DE apart that with the 'stronger' parts of the SR20 swapped with the 'weaker' QR25 parts (rods, crank and one other thing that escapes me...I just woke up, heh) it would actually stroke the QR25 DOWN but would make it a 2.2 litre, capable of more torque and still be as ludicrously overbuilt as the SR20 with exception to the blocks wall thickness. They referred to it as the 'SQR22DE'
it is possible to modify the stock crank and make it a stroker crank but i dont know how strong it will be. What the machine shop will do is weld additional metal around the rod journals and machine it back to round further away from the centerline off the crank. A stroker crank must use shorter rods also.
I know that TODA makes a stroker kit for SR's. I saw it in this months issue of Super Street (this is a good issue, packed with nissans, not hondas. I suggest you go pick it up). It was on a 240 but I think that it would also work with an FF application, being that it's all internals.
the stroker kit from Jwt was supposed to be a modified ka24de crank they never finished end of story. if you were to ever be serious about purchasing a stroker kit look for a guy named Andres Miko out of Miami