Cycling Jackets

7mesh kit has long arms.

I've got this one and I'm a man.
https://www.amazon.co.uk/GORE-WEAR-Womens-Active-Jackets/dp/B075S44DP6
Amazon is cheaper than Wiggle.
https://www.wiggle.co.uk/gore-wear-c5-gore-tex-active-cycling-jacket

I think it's a unisex jacket. The description sometimes says it's a men's jacket and other times a lady's jacket.

Most customer reviews seem to moan about it having long sleeves.
They're just right for me.

i'm tall and thin and the Galibier Tourmalet jacket fits great, there is some lycra extendable cuff thingy which make the arm fit great

Another expensive option is the Assos Sturmprinz has long arms with excellent cuffs. It's a great jacket, with plenty of venting - you don't overheat but it's not 100% waterproof. I've found that even in biblical rain I've been wet but very comfortable.

I've tried a number of jackets (Altura, Sportful, etc) and none of them are long enough for my simian-proportioned arms

Expensive answer? Gore Shakedry Stretch. Best fitting jacket I have ever worn, I didn't realise how important fit was until I spent 4 hours in the rain wearing this jacket, it was (almost) a pleasure.

However, the cat got mine, so while it's away getting repaired I bought a Galibier Tourmalet for almost exactly a quarter of the price of the Shakedry Stretch (£63). The fit of the Tourmalet is almost just as good, the material feels cheaper but it gets good reviews, so I'm looking forward to testing it out.

I have long arms and the Castelli Emergency Rain Jacket (in 3XL) works for me.