Portable battery jump starter which one to buy??

Been looking around the net for some time and I`m not sure which one to buy for my needs.
I live way up north here in Canada where temps get very cold and I need a unit with as much power as possible to turn these cars and trucks over.

I wont need a 24 volt as 12 volt will all I will need at this point.

I`m finding that allot of the manufactures rate there units in peak amps, cold cranking amps, and crank assist amps, which makes it tough for me to decide as im lost in these different measurements.I have narrowed it down to a few and was hoping someone can give me some advise which will be best for my situation.




Model JNC XFE

(http://www.cloreautomotive.com/sku.php?id=249)http://www.cloreautomotive.com/sku.php?id=249

Model JNC 950

http://www.cloreautomotive.com/sku.php?id=246

Model PSJ 4424

http://www.batterychargers.com/ProductDetail.aspx?ProductName=94080026

Model rescue 2600

http://www.quickcable.com/products.php?pageId=780

Thanks very much in advance!

hi gobby...
Acc. to me Model JNC 950 is better than rest.
it is suitable for the environment in which you live.

whats your thoughts on the jncxfe?

I heard it was a stronger unit than the 950?