No complications at all since many successful transplant has been made as long as u get a good and experienced mech for the job...Of course the wear and tear parts needs to be changed too such as the timing belt, bearings, oil seals, gaskets....bla bla...u know the stuffs...costs around RM700-RM1000 (depends on the engine condition too)
The halfcut price for this engine has risen tramendously since of very2 high demand and to make matter worst, the supplies are getting lesser by day...more deadly if ur getting the manual version...

I myself plans to go for the engine but since it's too costly (around RM3000 at that time) Ive taken a 4G15 instead (just to replace the old one)