LiFePo Battery Difference

I see these 4200 LiFePo batteries successfully used in pairs for starting a Mazda Miata. I found some 5000's and was wondering if that might not be better, but they have numbers that make me question it. With the stats below, would I better with 2-5000's or 2-4200's.
Capacity: 4200mAh
Voltage: 4S2P / 13.2v
Discharge: 30C Constant / 40C Burst
Max Charge Rate: 2C
Weight: 558g (including wire, plug & case)
Dimensions: 140mm x 45mm x 46mm
Balance Plug: JST-XH
Discharge Plug: 5.5mm Bullet-Connector
Capacity: 5000mAh
Capacity: 4200mAh
Voltage: 4S2P / 13.2v
Discharge: 30C Constant / 40C Burst
Max Charge Rate: 2C
Weight: 558g (including wire, plug & case)
Dimensions: 140mm x 45mm x 46mm
Balance Plug: JST-XH
Discharge Plug: 5.5mm Bullet-Connector
Comments
Starting a car in second or two is very different vs running a DC-to-AC inverter for many hours.
4200 mAh = 4 Amp-Hour
5000 mAh = 5 Amp-Hour
Do you have a URL link for each?