You mentioned wanting to use the monolights both indoors and out.
That means either a long extension cord or a battery pack of some kind.
Elinchrom makes good lights. They are digitally controlled which means accurate power adjustments.
They make two options that are battery powered, both at relatively pricy.
Other monolights can be powered by external packs, either made for the lights or generic.
Genesis lights, including the 300B with its battery pack, are entry level lights with an inconsistent power adjustment that has a digital readout.
At the present time, the Einstein from PCB, especially when mated with a Vagabond Mini, is the most versatile and economically efficient option.
Most modifiers (soft boxes etc.) can be made to work with just about any monolight via a speedring adapter. Elinchrom softboxes, including their octaboxes are an exception. The adapter is riveted into the speedring.