Impact Wrench Recommendations

[mboucher@hotmail.com Boucher]

I decided that an Impact wrench would be a good investment if I'm going to 
continue working on cars.  So I headed out to Home depot yesterday to pick 
one up.

They only had one electrical model, a "DeWalt" DW293 for $199 CAD.  I 
figured I'd bite the bullet and make the investment.  I thought that it 
would also double for a torque wrench because, as I understood it, impact 
wrenches usually have adjustable torque settings.

So I was surprised to see this $200 tool only have a button for one 
direction and one for another.  Since it provides 400+ pound/ft of torque, 
wouldn't this only be good for taking bolts off?  The highest torque bolt I 
can find on the front suspension is the shock piston ring which lists at 133 
pound/ft.  Many others are as low as 20.  Wouldn't a wrench like this strip 
most bolts that you attempt to tighten?

Is this a good buy, or can someone recommend an electrical impact wrench 
with an adjustable torque setting instead?

Incidentally, I thought about renting one from the Home depot tool rental 
center.  When I asked for an impact wrench, they pointed me to a tool that 
looked like an electrical drill but would provide a sudden forward 'impact' 
as if to drive a nail in.  Not certain who has the name wrong, me or the 
home depot rental people.