ok, reefr, do you already have your tank? if so, youve got the 2 most crucial items purchased/found, an that is the tank, and swf.com message boards LOL.
so lets see if we can get you set up for ur max of 225, an get u a decent tank goin at the same time.
ok, since your goin with a FOWLR tank, that is a Fish Only With Live Rock, you can use ur standard hood/light assembly that should of came with the tank, so your golden there.
now, hmmm, on the question of filters, youve got a 25g tank, so, without eating up your budget, and if im wrong, someone please correct me, u could probably get away with 2x hagen aqua clear 30 power filters, that should give you plenty of filtration, now, if youve got a filter already, just purchase a second one, 2 is always better than one in the power filter department
you should probably do 2x hydor koralia 1 power heads, those run about 22 bucks a piece on some sites, just shop around on google, just type in hydor koralia 1, an look through the shopping links they give you, i found em for 22 bucks doing that route, that should give you plenty of flow.
your gonna need a heater, im gonna say roughly a 100w heater should work beautifully for your tank
a thermometer, thats a must, since you dont want your tank to get too cold or too hot an u not know it or be able to tell it.
20lbs of live sand, and roughly 20-25lbs of live rock, but, start out with just 10-15 lbs of it, and slowly add to it as you have the finances, that will work out great for you there
a hydrometer, they're roughly 6-15 bucks at *****, depending ont he brand you get
a test kit, thats a must, the cheapest one you can find is the api, they're a decent kit, i think they run about 20 bucks at *****, whatever you do, stay away from the test kits that use the strips, they're notoriously innacurate.
and on the skimmer, id hold off on the skimmer and worry about getting the other things you need first, and getting your tank up and cycling, and stay on top of your testing, and your water top offs and water changes, and you should be ok for a while, and when you can afford it, then purchase a nice HOB skimmer
if you have any further questions man, ill be glad to help out
mike