Hi Annie,
Dipping in late, with some designs from Tad Roberts that might interest or inspire you. All have junk sail options!
HARRY, a 26ft sailing barge... a little heavy at 10Klbs, holds down the 'houseboat' end of the range.
(http://www.tadroberts.ca/services/small-boats/sail/harry126)at 10Klbs displacement
HARRY II, 27ft sailing scow... more what I think you're picturing, at 7Klbs. Junk styling and much more sleek than HARRY.
http://www.tadroberts.ca/services/small-boats/sail/harry226
NU-WA, a 20ft ply junk... approach can be enlarged to meet your wish list.
(http://www.tadroberts.ca/services/small-boats/sail/nu-wa20)
And LITTLE TILIKUM, 25ft ... a Thames Bargelet(!) at 7Klbs. Not plywood, nor entirely simple, but could be strip-planked or quick-molded. Once built, might meet your needs very well.
http://www.tadroberts.ca/services/small-boats/sail/littletillicum25
Hope some of these are at least eye-candy! 8)
Dave Z