I've been using the same 600A power pack for three years now. I discharge it completely on a regular basis beacause I use it to power a small 12v lunch box. It has started my truck (barely), inflated my tires (slowly...) boosted stranded motorists... It is loosing its staying power so I plan to replace it with a 800A unit. During the cold winter months you need all the cranking power you can get to start a cold engine.
Make sure it comes with booster cables, AC charger, 12V charger.
You can also purchase a separate solar panel to keep it topped up, but that should not be an issue if you use it regularly.
See my next purchase here:
PowerBox800Expect to pay for quality and I doubt anything under 600A can start your pick-up !