Ok, MTOW = Min or Max?? are you allowed out side help?
I'm just Past Cranbourne so if you want to come around i'd be glad to show you my scratch built/designed planes and give you some pointers.
check this out for probably the easiest scratch designed/built delta around
http://www.mugi.co.uk
or something like
or
http://www.spadtothebone.com/showcase11.jpg
http://www.spadtothebone.com/showcase44.jpg
or a canard
http://www.spadtothebone.com/showcase84.jpg
info on these planes and more are at
http://www.spadtothebone.com