This probably goes without saying but.... the higher the amp, the less charge time required. Big difference in charge time between a 10 and 20 amp charger.
Just saying....
Higher amperage comes with more risk too, a lower amperage charger is gonna be safer and offer much less risk of overcharging and causing a swollen battery or producing toxic gas should there be a charger shutoff malfunction.
Not if it is a “smart charger”. And that is the ONLY kind of battery charger you want. No risk at all to battery. These chargers run on programs that sense what the battery needs and applies it regardless of what the peak amperage the charger is capable of. They also act as maintainers. You leave them hooked up 24/7 when not on the water. Owning a good smart charger is your easiest way to maximum longevity and performance from your battery.
This link is to a great site that has great information on understanding storage batteries, their care, and about battery chargers --
https://batteryuniversity.com.