I'd look into a Red Dragon or Inaba Shidare.

Not sure there is a dwarf dissectum currently available,I think they will all eventually become wide...though we don't live forever :) I think your best bet is to choose a slow growing cultivar.My personal favourite red dissectum is 'Red Filigree Lace'.Gives the appearance of a dissectum in miniature as the leaves are quite small and finely dissected.Mine do seem quite vigorous in proportion to the leaf size,but I guess in feet&inches it is slower taking up room than norm.As mentioned earlier,I've believe 'Red Dragon' is considered a bit slower growing also.

The term 'dwarf' is typically applied as a factor of height, not width. And while most weeping disectums are considered to be dwarf in terms of mature height (depending on graft position and staking), pretty much all of them can get wide in time.

But there are quite a few dwarf cultivars that while not weeping or mounding exactly do offer a small and often sculptural appearance. I'd look at 'Beni Ubu Gohan', 'Fireball' or 'Kurenai Jishi' for red leafed varieties and 'Mikawa Yatsubua' or 'Hupps Dwarf' for green leafed cultivars. These are not the most commonplace of JM's so locating a specialty nursery locally or ordering online may be your best bet.

You might try 'Ryusen'. It's weeping though not red.