Very interesting...... is the weight of 996 Grams (2.19579 pounds) for the equipment only or is that everything? You said you length is going to be 2.3 meters (7.4 feet) and the wingspan will be somewhere around 6 feet?
There is a person on youtube who has built several different Depron Jets and they have very low takeoff speeds and landings..... the slowest I have seen (very scale like). Is your construction similar to his? http://www.youtube.com/neffwaffe
What are you using for foam?
Good luck on your build.... I will be watching!