I would probably be looking for something in the 0.03-5btc max entry cost.
And also how do these work, i assume when i by in to a tournaments at say 0.03btc then i just have that as my bankroll and play with other till the winner finally takes all?
Do these normally run for long?
I really just want one that i can enter without downloading anything, buy in for about 0.03btc and sit at the table, so what sites do i have available that would suite my needs?
What you are describing is the normal behaviour of a cash table, and not a tournament.
On a tournament you make a buy in, and then you will play according to the tournament structure. You will be given some chips, everyone gets the same amount, and then you will play with that until the end. If you run up of chips you are out, unless the tournament has re-buys etc. The blinds normally go up in a pre-determined interval, and things will get harder if you don't manage to win chips over time.
There are plenty of freerolls, on most poker rooms, so you don't have to risk anything if you don't want to.
As for cash tables, you choose a table with a low limit and you sit there you some coins and you play vs other players. The advantage here is that you can leave the table at any time, just grab your coins and leave. The blinds are fixed, and you are getting profit every hand you win.
In a cash table however you can't play for free, but like I said there are plenty of low limit tables, so you can find something for the limits you specified as well.
I used to play at betcoin.ag, and I enjoyed it. Don't play there for a while, so I don't know how things are at the moment.
When I used to play you didn't have to download software, although I prefer to do it, because I don't like the interface of browser play.
As for either to choose tournament or cash table why not try both?
Like I said, you have plenty of freerolls, so you can even play for free and win some coins.