Now that you're really confused... Different ideas from different aquarists each with good personal experiences.
First to toss out the myth, Sweet Aquatics has beautiful plants and offers good service, according to many here (I've never used them, being in Canada is troublesome for mail order plants as they won't ship here, plus I am lucky to have good fish stores around me); but their advice on needing 2-3 watts per gallon is completely inaccurate and misleading. There are enough of us on here with thriving planted tanks--take at look at my "Aquariums" photos, or Angel079's, or WisFish's, Johnny's, etc--to prove otherwise. I have less than 1 watt of full spectrum T8 light over my tanks, and it is more than enough--for what I grow.
What it comes down to first, is what you want in your planted tank. I've had a look at your plant list, some nice plants. With only one or two possible exceptions, all those plants will do fine under one watt per gallon of good light. I do agree that replacing your existing hood would be a good idea. I would get either a one or two full-length tube fixture. Angel079 now has one, and look at her plants growing. When I had a 55g, I had one 40w T12 tube and it was adequate for swords, vallisneria, crypts, aponogeton, Java Fern, Java Moss, Anubias.
Tom Barr has written that the first issue is to have minimal light. The more light, the more nutrients (CO2, nitrogen, macro- and micro-nutrients) will be needed. I have written the same many times here, and in the 4-part series of stickies at the head of this section, Part 4 deals with lighting. You can achieve a better biological balance naturally with minimal lighting. There is also the fish to consider; most fish in planted aquaria are forest fish like tetras, rasbora, angels, gourami, dwarf cichlids, discus, catfish--these come generally from low-light streams under the forest canopy and the fish do show better colouration and behaviours and health with subdued lighting and dark substrates.
I recommend either a one or two 48-inch T8 tube fixture, or one T5 fixture; T5 comes in NO (normal output) and HO (high output), the NO is very comparable to T8 (regular) and I believe uses slightly less energy so that is beneficial these days. The NO tube choice is somewhat limited though, so you may have to go with more expensive specialize tubes, whereas T8 can be found for few dollars at hardware stores as Angel079 has mentioned. I chose T8 over T5 last year when replacing two of my old fixtures for this reason. The nice benefit of two tubes of T8 is mixing spectrum (one full spectrum, one cool white) for maximum plant response and a nice true colour rendition of fish and plants. And floating plants can always be added (many of the fish do better with floating plants for several reasons anyway) to diffuse the light a bit.