it would be easier, but nowhere near as cool!
if the vl crossmember bolts into the VS, then you're *laughing*.... should basically be a bolt in job. (with a custom crossmember & tailshaft, obviously).
Prepare to foot a large auto elec bill, if you can't do the wiring yourself.
http://forums.justcommodores.com.au/vn-vp-vg-vq/47104-vn-luke-s-vn-12.html
Will be a similar operation to that...
depending on the power difference to holden's range of motors, if it's within 10% power to one of the engines offered on your VS, in Victoria, you won't even need an engineers certificate! (presuming that it DOES bolt in, meets the same emissions specs, and no chassis/engine modifications have been made)
There's another bloke that did an RB25DET NEO motor into a VN and was running 10's! - he popped up in the "My Ride" VN section a while ago, might be worthwile checking that out!
There's also another bloke on these forums that's doing an rb25 into a VG ute - he posted just recently with some wiring questions.