Asking for advice on Lipo battery manufacturers

Hello!

My own arduino related project currently runs off of AAAA batteries.
Now I've concluded that narrow LiPo batteries would solve a number of physical fitting issues, as well as provide a rechargeable power source, and it seems a good investment.

What I'm after is a LiPo battery that is 8 mm wide or narrower, 4-5 mm high or lower, with length being less crucial.

Searching online I've found several models of narrow Lipo batteries that fit the bill from two companies: Padre Electronics and Lipoly, and wonder if anyone have any experience of them, or have recommendations for other manufacturers that create the same kind of thing?
Normally I'd just buy some and figure it out, but I thought that asking for advice on this first might serve me better, since others here could have found a good source for this exact thing.

I apologize if this is the wrong section of the forum to post this in, but it seemed to fit somewhat to a general electronics question. Feel free to point me in the right direction if there is a better space to ask.

Deeply appreciate any help or advice, and thank you for your time.