:welcomera
Ok... Like the others, I'd say you'd need at least a 75 gallon tank with quite a bit of live rock for biological filtration, as well as a really good protein skimmer- the skimmer & live rock will help to maintain excellent water quality, which is required to have an anemone survive. Also, the live rock will provide grazing territory for the tangs & the starfish. Anemone's also require excellent lighting, so, like Maxx said, I'd go with at least 220 watt power compact lighting, but preferably metal halide lighting. You'll also need a few power heads to provide adequate water circulation. You may want to add a sump (VERY beneficial but not absolutely necessary), which would require you to have holes drilled in the tank, a water pump, & some plumbing work. Other equipment you'll need: tank stand, some sort of cover so your fish don't jump out, heater, thermometer, hydrometer or refractometer, salt, food for all the critters in your tank, substrate (unless you're going bare-bottom), & test kits for ammonia, nitrate, nitrite, alkalinity, pH, & phosphates, & probably calcium.
Before you put anything in a tank, research a LOT, and fully cycle the tank- this will take about a month. Then, before adding anything, research some more about the critters you intend to keep, what they require, and what they eat. Anemones are very difficult to keep, especially for a beginner, and especially in a new tank. I would wait until your tank is well established & you have more experience before attempting to keep one. Also, when choosing which kind of starfish you want to keep, keep in mind that if you ever want to keep corals, some starfish will eat them, so you should go with a reef-safe starfish (linckia's are a good choice).
Most importantly, be patient, ask questions, reasearch, & avoid impulse buying. If you take your time & research all of your purchases before making them, you can have a successful tank & avoid wasting a lot of money.