A bms in the pack just makes things easier to charge your cells and doesn’t really take too much space. You can do it without the bms, but it’s much easier with a bms inside. The only thing you’re doing is just removing it if you are only putting balance leads.
A good pack would be anything above 20A discharge in a 6-12s1p cell type build so that you don’t suffer from voltage sag from lower Amp discharging batteries. The higher the amp rating, the less you’ll receive. I haven’t used 25r in my build since people are now using p42a by Molicells. But they are good cells since people had used them before. The higher the amps, the more power you’ll have. Mine is 80A and its fine.
If you build your pack right, and take great care of your cells, any battery used are worth it. I like using 18650/21700 cells because they’re easier to work with than lipos (not to say lipos are bad. They aren’t. The cells are just easier to work with if you know what you are doing. Lipos are specifically made and need to be taken care of due to their polymer build).
In the end its up to you. To me, its worth it. But do know how to work with batteries before proceeding. I don’t want bad news.
Everything in esk8 is worth it. Those lipo zippy craps are good for beginners to get a custom to the world of esk8. If you can afford a new, well built pack, please do it. You’ll thank yourself. Lipos have to be removed every charge, kinda. Seems like a pain in the ass to me.