This is a pretty good list but the devil is in the details. Screen lid, substrate I've spoken about, hiding spot, dishes - those are all pretty straightforward aside from substrate.
Thermometers should be the digital kind with a probe or a temp gun (or both). I use a temp gun because I like to get instant surface readings anywhere in the tank. The probe kind are more fixed and take longer to acquire a reliable reading. Generally speaking though if you have an accurate reading of the basking surface and of a surface on the cool side, that's enough because it will tell you what the gradient is.
As far as hygrometers go, I don't use one. If the humidity is comfortable to you in the room it's probably fine. If you do get one, I'd be sure to calibrate it and test it out because I've seen inaccurate readings cause some unnecessary panic in the past.
The lighting is VERY important so I'd reserve a larger portion of the budget for this. The basking light needs to be a bright white light that produces heat. I've had good luck using the ZooMed Repti Basking Spot lamps. For a 55g tank I'd go with a 150w and then adjust it's height to get the correct temps in the basking area and cool end. You can also use PAR38 or BR40 halogen flood lights which are often a bit cheaper. I'd put the basking light in a dome fixture rated appropriately for the wattage of bulb and then put it on an adjustable lamp stand or on a lamp dimmer so you can fine tune the output to get proper temps. The basking bulb shouldn't get closer than 12'' or so from the basking spot.
For the
UVB light, I suggest using a T5 UVB tube if you're going with a 55g tank. They have much stronger output than the older T8 bulbs and have an optimal basking output at 12-14'' so they can be mounted right on top of the tank with the basking spot about 12'' below. The tube should run roughly 1/2 the length of the enclosure and be mounted on the basking side so that the intense UVB goes along with the high heat and has a gradient down to low UVB on the cool side of the tank. These are some good options for UVB lighting
This fixture
http://www.amazon.com/Sunblaster-904296-NanoTech-Fixture-Reflector/dp/B00AKKUBDQ
With this bulb
http://www.amazon.com/Zoo-Med-ReptiSun-10-0-Lamp/dp/B00AQU8HAO/
Or this combo set
http://www.lightyourreptiles.com/22-t-5-ho-fixture-high-output-with-arcadia-d3-12-ho-bulb/
It's a good idea to use a timer for the lighting. I use a dual outlet analog outlet timer from the hardware store and it works well. The UVB fixture I use has a ground pin so I use the timer with 3 prong ports. Don't need to go crazy on this one, just a cheap one from the hardware store will do. This will let you set it and forget it when it comes to turning the lights on and off and provides a consistent routine.
For nighttime, you don't need any additional heat if the temp in the enclosure stays above about 65 overnight. It's natural for them to have a cool down period overnight - to an extent. If the temps drop lower than that, I'd use a ceramic heat emitter. They produce heat without visible light which can disrupt sleep. I use a low wattage CHE during the winter. A 50w mounted about 20'' up is enough to bump the temps into the high 60s/low 70's which is plenty. That's on a separate timer so when it's needed it comes on an hour or two after lights out and goes off an hour or so before lights on.
The spray bottle is for misting their noses to provide water. I'm more in favor of using a dropper or plastic syringe to drip water on their nose so they lick it up. I also provide baths regularly which gives them another opportunity to have a drink if they want. They will get most of their
hydration from food so be sure the bugs are well
hydrated and the water will be supplementary.
Live food will vary. I suggest using either crickets or dubia roaches as a staple bug. Both will need an enclosure which could be made from a lot of things. I use a spare 20g tank with a mesh top for my dubia colony. You can also use a large rubbermaid bin with a screened hole cut in the top which will work just as well. If you decide on building a dubia colony, give it a few months to get started before feeding them off and they'll be an easy to care for and cheap food source going forward. Crickets are cheaper if you order them regularly in bulb but they aren't as hardy and are a little more of a pain to care for. You'll also want some supplementary worms like Phoenix Worms or silk worms to have on hand for variety. This is in addition to fresh salads which young dragons often ignore for a while in favor of bug protein to help support growth. There is good info about what to put in salads here
http://www.beautifuldragons.com/Nutrition.html
It's important to have good calcium supplement. If you go with a T5
UVB light, I'd use plain calcium without D3. The D3 supplement is for use in enclosures with lower output UVB lights which aren't strong enough to allow natural D3 synthesis. It's a bit of gray area but that's what I go by. The calcium should be applied according to the label but in general, dust bugs at every feeding with calcium and if you get a multivitamin, use that once or twice a week in place of the calcium.