Ditto on the Westeria, mine grew very well under a 6500K (last pic bottom right) Coralife Ultra grow light... it started morphing the 2nd day I planted it. It's since been changed to a Dual T5 6700K (first pic top left) and doing well. In this picture you can see the top cuttings have been lopped off and planted underneath and still doing great, morphing faster. Inadvance, Yes you can cut tops off IF they have a 1"-2" root shoot coming out of a stem rim line segment. Just cut 1' below and peel any leafs between root and bottom.
Westeria grows great! That tank has only been up 3 weeks and the Wisteria has only been in it 1 week. Both 10gallons are far from complete.
I also, have Red ludwigia and it grows well AFTER about 2-3 trimmings to clear out soggy roots. For some reason I have problems planting this at first in bunches and found that it likes a VERY shallow planting... anyone else have the same results ?
Also, some more suggestions for low light would be Bacopa (either Moneywort or Lemon Money wort) and Cardnial plant. Cardnial Plant would look very very nice as a mid or foreground with the Java fern.
Good luck