I can't reply to your PM for some reason so I'll put it here....
Please read this thread.....
http://www.rollaclub.com/board/?showtopic=8093
As I said in your thread, rollaclub members are always more than happy to help you. However, you will find we're hesitant to do so if its obvious you haven't spend the time looking around for yourself.
Asking a question like "what the easiest engine conversion for ....." is opening yourself up for a world of greif as you've found. Just remember - "Opinions are like arseholes, everyone has one but you don't neccissarily want to see everyones".
If you ask a more specific questions (and show that you have done some research) then you'll find you'll get a lot more help.
To answer your question breifly (and Toy-yoda did do a pretty good job of this via PM) the easiest "bolt in"upgrade is a 5k. 7k is next easiest with sump or cross member mods. A series would be the next easiest but this requires some other mods like a hydro clutch. Any other motor is possible but it then becaome a matter of how fat your wallet is!!!
Cheers,
Si.