Hello

I'm pretty new too biking, I've got a CCM Riptide right now that I've had for a few years cause I wasn't really into biking for the last few years, but for the last 3 months I've been riding the piss out of it
It's time for a new bike

The bikes I've been looking at are the(all 2004 models)
Trek 4500
Specialized Rockhopper
Kona Fire Mountain
All are within $50 of each other, so the price on them isn't really an issue. And having rode my CCM Riptide for the last 3 months through dirt, mud, snow, and pavement makes anything really ride like a dream. I haven't test ridden any of them yet, but I will, but the store is 2 hours away(going to be moving to the city in fall, so warranty/lbs help isn't an issue) So I only have 1 crack to do this.
My question is, if they all ride very similarly, and I can't really tell much of a different, which should I buy?
They're all great bikes, and would b e happy with any of them, from what I've learned from trolling around on this forum I'm thinking the rockhopper would probably be the best
Thanks for the help/suggestions If i get any
Oh yes, also, I'm 5'8" 180 right now, what size frame would you guys recommend?
I know the Kona and Trek go 16-18-20 and the Specialized go 15-17-19(please correct me if I'm wrong)
I'm mostly going to be doing rough terrain trail riding with this, and commuting 8km round trips to school each day
Thanks
