Sorry about my first reply. So much about these tanks is personal preference. I will try this again. If you have not already bought a tank, try not to limit yourself to the standard 55 gallon. While shallow tanks are great for showing fish off, a lot of people think they are harder to plant because of lack of depth (not much depth for foreground, mid-ground and background planting). You might find, after thinking of it a bit it is worth going to a 75 gallon, or that a 30 gallon cube might show off your plants better. I personally chose a 58 (which is essentially a 75 with 12 inches cut off). There are tons of opinions and options - do a search on the board too.
As for light, the rule of thumb is about 2 watts per gallon for what you are talking about I think. Some lights are more efficient than others – aesthetics, diy skills, and personal preference are all important here. I have dropped almost $400 into my main light (a 250 watt metal halide pendent – and at the moment am lighting my tank with an odno shop light that cost a whopping $40 . No they are not comparable – I still love the hqi pendent for various aesthetic reasons– but I think the plants could care less. If it was not in my living room, I probably would not either.
Actually have two shop lights on the tank, one ondo,one nomral output. They are pumping arround 170 watts - but are 4ft bulbs over a 3 ft tank. Your guess is as good as mine on the watt/gallon I actually have.
same stuff holds true for filters. I could say get a Eheim 2217. No doubt in my mind you would be happy. Others will say get a xp3 (more flow, maybe a little louders). (looks like a good current thread and heated discussion is happening on those two today (Eheim Classic 2217 Vs. Rena Filstar XP3
) On the otherhand, perhaps you would rather spend $30 and use a mattenfilter.
same goes for substraite as well I guess - but will try not to talk about mineralized topsoil... Each of these ideas can save money - sometimes. On the otherhand, you probably would not regret getting the good stuff, and sometimes people do regret cutting corners.