Okay, here goes... got your pm...
I can't exactly call myself a hovercraft expert - I have not made enough mistakes to qualify myself as one yet. What I did with my hovercraft (in the airboat section of the forums) is I based the hull off of plans for the griffon 2000 on mark porter's website. You can scale them to whatever size you want. He also has the skirt layouts for the vehicle. Then, after you build the hull and skirt, and both are working, you can concentrate on building a LCAC-looking top. Since you have two ducted fans (of relatively small diameter, this could get interesting) You will need to build light, and relatively small. From my experience, the best thing you can use for your lift fan is a small diameter propeler in a duct - it's cheaper and more efficient than an EDF. For forward thrust, you can probably get away with the EDF.
About plans for hovercraft - not may people build them, so your best bet is to study photographs and plans of the real craft you intend to model. About your skirt problems - please post some pictures of your craft, they are worth a thousand words! (a good skirt helps with ground clearance, not so much stability and sliding) Sliding is an inherent characteristic of a hovercraft (think air hockey puck) trust me, its part of the fun of driving one. If you don't like it, use a gyro to dial it down. I am waiting for mine to come from hong kong and will post how things go in my thread. BTW, I think you will get more responses in the airboats thread... a few people down there have built hovercraft as well.
IMO one of the best rc hovercraft websites out there: www.model-hovercraft.com/2000tdx/2000tdx.html
his last craft has four ducted fans for lifting... quite an interesting design if you are interested!