What is the best battery to use in APC BX1100CI-RS UPS?

Question

Uninterruptable power source

Hello.
In the middle of the night, not being under load, the above UPS began to squeak heart-rendingly and blink a red lamp.
As I understood from a cursory search, the end of the battery (and possibly the charger) has come. I have had this device for at least 5 years. I’m thinking of buying replacement batteries, but I don’t know which one to choose, there are a lot of options and reviews also vary greatly. Can I take an increased capacity of 12V 9A (instead of 12V 7A), should I keep the charge longer?
In general, I look forward to constructive suggestions. I plan to replace the batteries not by myself, but through a person who knows how to use a multimeter, since most likely it will be necessary to repair the charger.
Therefore, first of all, you are interested in which battery you would choose and why.
Original batteries are 2-3 times more expensive, about 5 thousand, I'm not sure that this price is justified.