Have a look at eBay there's loads on there new and second hand tanks.
There used to be a myth with marine that you need a minimum of a 3 foot tank .
But then people do have pico tanks and nano tanks which are small .
For what you are looking at I'd recommend something around 2 ft square minimum really.
What you need to do is sit down and think I want these fish then take into account how big they will get once they are adult size,they need room to swim about .
Also you need to take into account adding sand/gravel and live rock will take up a bit of room so will coral,anemone etc.internal or external filter.
And you don't have to have a protein skimmer,
Have a look around when you find one or a couple post it on here and we will all give you a honest opinion if it's big enough and suitable .