Apple only uses their original batteries, however with the SE1 it's really at a limit with modern apps and websites so battery life is going to be awful no matter what. Specifically the SE iPhones have mediocre battery life right out of the box when they were newly released. Thus, I question whether it's worth investing the $70. If you absolutely want to extend its life by another 8-12 months then that might make sense.
On heavy usage I suggest you replace the entire iPhone though. I have a SE2 that I used heavily with over 1,000 charge cycles in the short 2 year lifespan it had. I was up to about 4 full charges per day as connecting Airpods, Watch, Homekit sensors and continuously using it throughout the day made the battery drop a percentage each minute. Essentially unusable.
And while a new battery would reduce the amount of recharges it would still never get me through an entire day (since it couldn't do it when it was brand new in 2020 either). So I saw no point and replaced it with a Pro that lasts the entire day. It still goes through a charge cycle every day but I no longer run out in between. Makes all the difference that I can leave the house without a power bank.
If you can easily switch the battery out yourself with tools you already have then you could save the money and get the ifixit one. The $70 includes the convenience fee of not having to do the work yourself. For my old SE2 I decided to keep using it for home automation in my home where the battery doesn't matter. That way I can still use it for a long time to come.