Just ordered all to parts for a stroker build in my zj. As was stated it's not going to be cheap, but if you need an extra 100 ft-lbs then its an easier route than a V8 swap and a lot easier than a diesel swap. I looked into several options before deciding to build one.
option 1: Precise engine rebuilders in Calgary have a 4.6L shortblock for sale for $2000, but I think they'd take less. Apparently, a customer ordered it and couldn't pay for it. In the end, it wasn't exactly what I wanted so decided not to. Also, their customer service is questionable.
option2: order a prebuilt long block from golen or Hesco out of the states. Stay away from Titan. They are the cheapest, but lots of guys have had trouble with their engines and spend more in the end. Hesco is rated as the best, but $1000 more than golen. Golen has a realy good rep. I would go with them.
option 3: do a ton of research and figure out what you want. follow a proven recipe and go for it. This is the recipe I chose:
http://telusplanet.net/public/cdkruchk/Stroker%20Recipe%202009.pdf I'm getting firebolt to do the machining and assembly. In the end I expect it to be in the $3000 range.
There are also a ton of info available on jeepstrokers.com