Right, and yes i want a heater and i have been a coldwater fish keeper for 2/3years, so basically I'm saving up for a huge tank maybe 30 or 50 gallon, i want big colourful and vibrant and easy pleased fish that can with-stand power cuts
If you go with a 55 gallon, your tank won't drop temperature as much when the power goes out. And you'll have more fish options.
I didn't know you'd kept goldfish already. If that's the case you can go straight for more fragile warm water fish.
Seriously look into the Malawi cichlids. There are a lot of really cool species, they come in pretty much every color. Red, blue, orange, yellow, brown.
Also interesting are the larger gouramis, like the three spots and the pearls. And then there's Angelfish. They're interesting too.
If you tell me what you're interested in I can zero in on a good combination of fish for you but I need to know your general area of interest, and how large this tank is gonna be.
Also, keep in mind that your fish selection will affect your tank design. You want to keep angels with nice broad leaved plants to encourage spawning. Gouramis benefit from bunches of floating plants for their bubble nests. Malawi cichlids benefit from a big rock scape, etc.
If you went the lightly planted route, a 55G tank could house
Pair of angels
pair of pearl gourami
pair of bolivian ram
small group of dwarf neon rainbow
bushynose pleco
You'd want smooth rocks here and there for the rams to spawn on, in one corner a floating plant for the gouramis, on the other end of the tank, a sword plant for the angels, (or a very large anubias or java fern) and fill out the rest of the tank as desired. A piece of driftwood for the pleco would be a must too.