Wow you found an absolute BARGAIN! I've recently found some cheap MEOS as well and trialling them now (on DS who is 20mo), so far I'm quite pleased and impressed! I've come from All-in-Ones (that I've had to boost for proper absorbency) and so far the MEOS are lasting just as long without any extra boosting and not had any leaks yet.
I'm using them with the Mother Ease Airflow Wrap. Although for newborns you probably want to go with the Mother Ease Rikki Wrap as it has a gusset so will be much better for poo containment. It closes with Velcro though so once your baby gets to toddler age it might be better to swap to Airflow as they close with poppers. The Mother Ease wraps are sized, so you'll need to get Small for a newborn, then Medium etc. The Medium is supposed to be from 10-20lbs but they're still a good fit on my DS (27lbs), the Large is quite big on him still. I guess you'll find out what suits best with your particular baby. There are many other brands of wrap out there as well (some sized, some one size but adjustable) but I haven't personally tried any. I'm looking to try some Blueberry Coveralls as the designs are just gorgeous.
Also for a newborn you don't need to use the pop in liners on the nappies (as you want to make them as small as possible and the liners make them quite bulky). You might want to use a fleece liner. These are usually used to catch the poo so you can flush it down the toilet, but newborn poo is so runny you can't really do that (you can just pop it all in the wash), but the reason I'm recommending fleece liners is because the terry MEOS do tend to feel a bit rough, so it'd be nice for the baby to have a soft layer against their skin (moisture just goes through the fleece, so it's effectively a soft stay-dry layer).
Just a note on the word liner. The MEOS uses the word liner for the pop in pad, which is actually a booster (it creates more absorbency). Usually when you read the word liner what is meant is either a fleece or disposable thin layer (that has no absorbent properties) that is used to catch the solids so you can easily flush them down the toilet. No need to use liners for a pre-weaned breastfed baby (sorry I have no experience with formula), but once they're on solids you probably want to use them.
Hope this novel is helpful
Is your DC1 still in nappies? Could be good practice to use on him/her.
I forgot to change DSs nappy today in the afternoon (insert bad mummy icon) BUT it means I can now safely say that the MEOS with insert (regular cotton ones, not bamboo) can last for about 7 hours without leaking! And his skin looked fine as well.
Also yesterday we were out in the car for 1.5 hours and that nappy lasted 4 hours (that's the normal time I'd go between nappy changes for DS as long as he hadn't done a poo), which my AIOs definitely wouldn't have done without a leak.
MEOs were one of my first nappies, they were very good, the ME Sandy's is also a very reliable option, esp for babies who do poo explosions There is also a Popolini One Size which is extremely similar to the MEO and just as good in my experience.