Hooked but I have questions

I never in a million years thought I'd be posting here about cloth nappies.

I had my son in disposables and it wasn't until I ventured over here to have a peak and got curious, a beautiful BB member sent me 2 itti bittis - now I'm sold.

So my questions are:

My stock is:

8 x OSFM Bumgenius with inserts - new
8 x small itti bittis - pre loved (I thought I'd use these until missy is bigger in case the OSFM don't fit well)
2 x BBH Bamboo fitteds with covers - new
2 x BBH AIO's Med size - new

Are these enough? I figured I'd use the BBH as night nappies and have the 2 sizing to allow growth, but the Bumgenius should do....

What else do you think I'll need? *dumb question sorry* Should I also use a disposable liner on top of the insert?

I am a FT SAHM - so washing every day isn't an issue - on wet days only I'll use the dryer.....

Do I need more? Am I missing something? Will they last the 2 years I expect to get use from them?

I found it easier when starting out to build up what I needed gradually, as I got used to what worked for us, so if you don't have all you need now, it doesn't matter so much.

Smalls probably won't last you a long time. As for the others, how long they last depends on how they're cared for and how fast your child grows/how heavily she wets etc. The more often they're used, the less time they'll last.
Most people get a good length of time in mediums. OSFM didn't work well for us, so I can't really comment on those in particular as we stuck to sized AIOs -mostly Ittis. I think I had a rotation of about 20 that were just beginning to lose their elasticity after about a year's use. But that was at toddler age - younger babies go through more changes.
You might not find the OSFM a good fit while she is little, which would leave you with only the 8 smalls, not likely to be enough for a young baby. You might like to look into prefolds and a few covers for the early months while there are so many changes.

I personally like flushable liners, but it's not important to everyone, especially at the newborn stage.

It's so easy to get hooked isn't it? It might seem a bit overwhelming at first, but I found reading through older threads on these forums to be really helpful when I started - if you can find the time :D Well done on just jumping in there too, btw! Have fun.