I'm not sure what's necessary but its a 48 in deluxe florescent aquarium reflector . 120v , 40w and 60 hz.
I assume this is T8, not T5, with a 40w 48-inch tube. This is standard. This we can consider low to moderate lighting, depending upon the tube. The absolute best you can have here is a Hagen Life-Glo which is 6700K (48-inch T8 is 32 watts, again standard). These are available from some fish stores or online, and are expensive (compared to most other tubes). If this is too expensive, you can use a Sylvannia or Phillips T8 48-inch Daylight at 6500K available from hardware and home improvement stores like Home Depot. I have two of the Phillips over my 4-foot and 5-foot tanks, and that is just moderate lighting.
T8 tubes come in a given wattage depending upon the tube length and manufacture so there is no higher wattage unless you have longer tubes. You cannot add intensity unless you add more tubes, but within the individual tubes there is some difference in intensity. The Life-Glo is a more intense light because of the phosphors, so it would be my suggestion. It is without question the best T8 lighting for a planted tank. The spectrum is very good, and scientifically-controlled studies have shown better plant growth with light in this spectrum.
Beyond that, even with the one tube you will have success if you stay with low-light requiring plants. Amazon sword plants usually work, and the pygmy chain swords can bee a nice substrate cover though not a "carpet." Java Fern, Java Moss and Anubias, all of which attach to wood or rock, are low light. Crypts can sometimes work, but these tend to be very fussy plants and sometimes they will grow, sometimes not, under this low light. I would forget any stem plants because these are fast-growing and thus high light requiring. One fast growing plant group that will work and is advisable are floating plants. Water Sprite is the best of these. Obviously floating plants will further reduce light getting down, but keeping them thinned out should still work.
Another option here is to go with floating plants alone, and no lower plants, but instead lots of wood chunks and branches, and some dried leaves on the substrate. This is a very natural habitat for most forest fish, and they will show brighter colouration with the more dimly-lit tank.