Thanks for all the input - it seems that my shorter wider thoughts may have been a little on the extreme side for a small person (width particularly).

The lines I've been messing with are currently 2m (6'6" near enough) x .5m (19.6"). In light of your collective comments I think I'll keep the same basic lines (not greenland-esck at all) and re-scale it to 2.4m x .45m (7'10"X18"). 2.4m means it can stand on end in the garage - no reason other than convenience!

No doubt all will become clear with a 1:1 scale drawing on the garage floor.

I'm hoping to avoid outriggers if I can, or at least grow out of them smartly.

Thanks again for your thoughts!
Simeon.