as long as its the x18xe1; then no problem using o.e management, as with x14/x16 just needs immob skipping past i believe.
Look at' warren g's garage' thread (corsa-c.co.uk) hes transplanted x18xe1's into corsa b's keeping o.e management.
http://www.corsa-c.co.uk/forum/showt...=1#post5003791
But yeah the engines are plentyful, not too old and cheap as youre finding. I say sell the big block fitting kit, keep your cav and at £150 the x18xe1 youve seen could be a bargain. Just check its not the x18xe. Which is a big block.