I have a 440 sq ft shack. Weekend use. Propane heated. No electricity. No well.

I will end up getting a Honda EU2200i for powering tools but do not want the noise of a gas machine for the other 99% of the time.

The battery pack is for evening use. Portable to take home and recharge during the week. I'm wiring the shack this spring and the battery pack will be the power source.
Later on I may add solar panels and a controller.

To power 3 LED lights, a 12V 3 gallon/minute water pump twice a day for a quick rinse or pump grey water from a sink, charge cell phones.

Question
Not looking for the cheapest and also not a cadillac.

What do I need?:

1 - 100Amp hr LiFePO battery such as the Battleborn
1 - Battery Management System
1 - Modified Sine Wave Inverter
1 - Charger
Assorted wires, connectors, plywood, wheels

Suggestions, links, questions and comments would be great.

I had originally thought of a Dewalt 1800 Watt Portable Power Station and four 20V MAX XR Lithium-Ion Premium Battery Pack 6.0Ah which would cost $1100 cdn +HST

How far or close am I?
Should I build a battery pack. It would cost more. Fair enough or use the Dewalt?