i had a similar issue, needing to replace rigid brand pumps with crazy amp draw.
I went with this model and I was able to get it done for about $1,000, including the battery.
The bonus of this model is the 20 amp charger, so if you need extra pumping, both pumps will run without draining the battery, when power is still on. and you can add a second battery.
ive been very satisfied with this set-up. redundant. and you can wire it to your house alarm or a dialer to let you know if power fails or the primary pump fails.
i was able to source the combo set up here