We have a reversable seat, and I'm glad we got that one because DD is still rearward facing at 11 months - she's still a littley. They have an insert for newborn babies, and when they get a bit bigger you remove it.
Having said that, there were times when I woke DD when taking her out of the seat and wished I had a capsule. Sometimes, if she was tired enough, she'd transfer from the seat into bed just fine, but mostly she'd wake. Hiring seems like a good option. (I'm not sure about the capsule attachment to a pram option? I was told by the antenatal nurse that having them in the capsule all the time was bad for their back? )
Anyway, if I were you, I wouldn't buy both a reversable seat and a capsule - I'd hire a capsule or just not bother with it. Reversable seats and capsules are expensive items... But of course it is your call They are both safe options.