I really wouldnt bother mate,
Far easier to buy an Altezza and add the lexus goodies (heated seats etc)
but if you do. the dash loom etc should be ok, only issue is the speedo is setup for 6 pulses (ie 4 cylinders) and your fitting an engine giving out 4. So an altezza speedo is possibly an idea as well. should pick one up pretty cheap and plugs straight in.