My mother hates all the holes I put in "her" walls :lol: You can probably do a really nice imitation ADA solar with a MH, the right bulb (off Ebay) and some conduit.
UG filters aren't ideal for planted tanks unfortunately. There seems to be debate one whether or not they are still a sufficient form of filtration. Phil Collis has used them in his fishroom so maybe he could shed some light on the matter?
I might be able to swap you some easy to grow plants next time you drop some lovely guppies off