Test Kits Suck,
Do this instead.
Buy a 20gal tank = $20
100w Visi-Therm Heater ( not sure of cost i forget)
Get a hood and canopy many would suggest AHSUPPLY.
And a filter...varies on what type you want.
You can always go with a kit...just remember..kits are VERY BASIC. You'll end up paying alot more like i did if you ever decide you want plants.
You can always try craigslist or ebay for used tanks that have been modified. Garage sales are nice.
Check your local Petco. Most of them are discounting their Aquatic Gardens tank kits because All-Glass changed their name to Aqueon(sp?). The kit is made up of Tetra, and All-Glass equipment. Right now they should be 20% off, and may be discounted more in the next ad. I got my 20gal kit for $69.99, not including employee discount.