just get a desklamp for the tank with a compact florescent in the right spectrum (home depot sells some that are 5000k i believe, or maybe they were 6500K... whatever, either works just fine, as does 10000K).
for you plant list, i would swap out "dwarf hairgrass" (e. acicularis) for belem hairgrass (e. belem). its smaller, so its more in scale with the tank. e. acicularis is tall enough for a background plant in a 2.5 gal. its just a super small tank.
are you gonna go CO2 or no CO2?
Eleocharis parvula works well too. I don't know if its smaller than E. belem but it only grew to an inch max in my 2.5. Plus you can buy it in the little plant packages at petsmart.