Great job with the Raspberry PI, breadboard and all!
I donot know whether you are still looking for one but here we consider the Meteograf Barograph with paper roll the best. It runs on a household battery, weighs 500 gr and costs in the US 890 dollars which is cheap compared to the European price tag of € 955 which amounts to 1110 dollars. You can take it easily from the ship to your home and v.v.
https://www.celestaire.com/product-category/weather/meteograf-barograph/