Hello to everbody!!!

Im a newbie and need help !

Im in the process of designing my first build and could do with a lot of tips and suggestions on ways to go ie (ducted fan vs unducted prop )hull height from floor to top of skirt (planing surface angle)if this is paramount in a design, power to weight ratio s, whats the best floatation medium expanding foam vs solid substance , etc etc a quick insight into my build plans are as follows .

Im using aluminium as the hull medium it will be built with some aircraft design in mind ie skeletel trusses etc for rigidity and i had thought of injecting the foam medium into the cavity so as i can finish the welding and fabrication without causing undo heat to the foam ! this also gives a good level of density to the craft when the foam medium drys, whats the best skirt/ material? ! the engines i have for lift and thrust are as follows ,

lift= a MZ 34 313CC 27HP AT 6250 RPM 2 STROKE

thrust= BMW R1OO WITH ROTAX DESIGN GEARBOX COMISSIONED BY SCRIMINGER ENGINES i think the engine is approx 90 hp

i did get a prop with this engine its a 3 bladed carbon fibre approx 2 metres dia .

im ok on the welding and fabrication side but could do with some help with wheres the best to mount lift fans , thrust aspects should i go with pulleys or hydrolics who is going to rip me off and who knows what there talking about(shops)etc

any help from those who know what there talking about would be a great help!!

thanks andy