what plants look nice in an indoor/garage winter tub pond?

[CT_]

And, how would you plant them?  It's going to be a bare bottom tub with a medium sponge filter and whatever plants.  I've got SOFT water too if that matters.

 

I'm thinking Brazilian pennywort because it can look like little lily pads if it reaches the surface. 

What else looks good from above.  Would a pot of aqua soil work to plant plants?  Can I keep them in their rockwool forever?

 

I've never had water wisteria or water sprite I hear those are both easy and fun.  pogostemon octopus?

 

[Streetwise]

I am obviously biased but this would be a fun opportunity to try organic topsoil with a thin gravel cap in a pot or two, even if you try other techniques in other pots. Diana Walstad provides a useful reference book for all freshwater aquarists.

[Isaac M]

This sounds like a beautiful opportunity to try different ways of planting. I am a little biased too but I agree with @Streetwise, gotta have at least one organic soil pot. A organic soil pot with either crypts, a sword, vallisneria or even a crinum. You can also do aquasoil, plants should be fine in the rock wool, normal gravel or sand for the stems, eco-complete, etc. 

Pennywort would look nice, you can even float it. 

Plants that I would go with would be dwarf aquarium lillies and/ or a red tiger lotus, ludwigia (grown under and/ or above water), giant hygrophila (corymbosa, above water will flower as well), cabomba, water wisteria and a larger leafed anubias. 

I would also take this opportunity to grow marginal/ bog aquatic plants. 

[Odd Duck]

I think @Isaac M has a great idea with red tiger lotus (Nymphea lotus ‘Zenkeri’) since they put up very pretty multi-colored pads.

I’ve been wanting to try mosaic plant, which would be gorgeous in a pond (Ludwigia sedioides).  It even gets a fair amount of red with higher light levels.

Pic from an on-line ad for the mosaic plant (not the round lily pad).