Need some recommendations and advice on LiFePO4 battery build

[EastFalcon]

I would like to put together a 12V 4-cell lithium (LiFePO4) battery together for my travel trailer and I need a few recommendations and advice.

First, is was thinking of purchasing the Grade A EVE cells (280 ah to 304 ah) from a site like 18650batterystore.com or DocanPower.com as I heard that these are reputable sites. Is this true? Are there other sites that I should consider?

I was planning upon using an Overkill BMS (https://overkillsolar.com/product/4s-bms-120a-lifepo4-threaded/). Its got temp protection and it will handle a 120 amp continuous discharge, which is more that enough for my needs. Is this a good enough BMS? Should I consider another?

Lastly, I've read that I'll need a variable voltage DC charger so that I can initially balance the cells but I'm not sure what to buy. Thoughts?? I did find other posts requesting the same thing, but the links no longer worked. Would this one work that I found a Amazon work or should I go larger? (https://www.amazon.com/NICE-POWER-Variable-Adjustable-Switching-Regulated/dp/B0C69NHPKD/ref=sr_1_17?crid=1ZVOJ0IMYR7F0&keywords=variable+power+supply&qid=1698168319&sprefix=varia,aps,97&sr=8-17&th=1)

Your help is appreciated!

Thanks

I have been pretty pleased with v4 sunfunkit, I used there kit and cells from 18650battery store. There seems to be some quality issues with docan and sanded / relaserd qr codes so I suggest you read up on that. Look into the v5 kit if you need heating.