The bikes you picked are cheap and shouldent realy be called mountain bikes. But it is really up to you, my first mountainbike was a Pacific XL2 that I paid a grand total of $98.00us at my local department store. I rode this bike every where my friends did on there real mountain bikes and it worked almost as well. So if you are comfortable with those bikes and like to by a new bike every year then go ahead and buy, but go with the Iron horse. If you want something that will last you a long time and is good quallity go with a gary fisher or something.