1978 KZ650-C2 battery replacements

Basically, the battery in my dad's old KZ650 went bad and the bike is just covered in surface rust due to our shed that it was stored in. I plan on restoring the motorcycle to its once glory, but in order to do so i first want to see if the electrical system actually works. The batter that was in it is about 3 years old and untouched and of course tested bad. With the battery in and key turned, no lights no nothing. Hooked it up to a battery tender that also tests the battery to see if it is holding a charge (to which it failed) so I'm trying to find a new battery online. The ones that supposedly fit the bike on some websites are bombarded with awful reviews and I really don't want to be spending money on something that's gonna need to be replaced in 2 weeks or less.
TL;DR Recommend a battery that fits a 1978 KZ650-C2 that is common enough that it can be found fairly easily on sites like autozone or others.

I'm currently running a Scorpion AGM from batterystuff.com. It's now a tad over 3 yrs 3 mos old, and I keep it on a smart charger whenever the motorcycle is not ridden (Ctek US 0.8 smart charger & VC97 digital multimeter). My previous scorpion agm lasted exactly 2 yrs, but I didn't use a charger much & didn't have a smart charger at the time. Yuasa batteries should be good, but I did not see an AGM there.
just in case. make certain the battery you get has the correct pos (+) & neg (-) orientation.

www.yuasabatteries.com/battery/yb10l-a2/...tom&vehicle_id=29133

www.batterystuff.com/powersports-batteries/sYT10L-A2.html

www.z1enterprises.com/battery-cb10l-a2.html

I've owned my 1977 KZ650-C1 since it was new. I have always used Yuasa YB10L-A2 batteries. They last at least 6 years or more. Ed