erebusting

I was going to setup a new system sometime soon and I was wondering, should I use raid 10 (thats 0 + 1 right? sorry if not, but I am reffering to 0 + 1) with say 4 500gb drives, or just go all raid 0 with 2 1tb drives (more space, but no backup)...
I do have an external 1tb drive I can use for backing up anything important...and I don't feel like I would mind having to reinstall windows and such as long as my data is somewhere safe....

but this is my first time attempting RAID so I was hoping for some advice? I heard raid 5 was recommended over 10 because it allows more disk space usage- but i noticed it does not perform as well as raid 0 + 1....is raid 0 reliable? also I was thinking maybe I could do raid 0 with 2x 1tb drives and back those up with a raid 1 2tb drive -is that possible, if yes is it a good idea?...

keep in mind -I do not want to get 4 1tb drives for raid 0+1 because I believe that would cost too much for me right now.....and I would like to get the best performance...maybe should I get like 6 300gb hdds ? and use raid 0 + 1 , about 900gb each array....