Ocarro will take a Cybex car seat which means it takes any infant car seat from the following brands, as they all use the same adaptors:
Avionaut
BeSafe
Cybex
Maxi Cosi
Nuna
Recaro
Also, any Joie except Joie Juva; Cosatto Dock; Bugaboo Turtle; Axkid Modukid Infant (with additional adaptors) and Venicci Ultralite, which is the UK branding of Avionaut Ultralite.
You can't put a Britax car seat on there, which is the only other brand I'd suggest to look at as their infant seat has some good features. The other non-compatible with M&P buggy options I'd suggest are the Joie Juva simply for cost as you won't get a cheaper seat than that, although it really is a basic seat, and the other option to look at are fixed, isofix fitted spin seats which turn towards the door of the car and will last until approximately 3-4 years old, typically costing around the same or a little bit more than a high-end infant seat + car base combo.
However. Crash safety wise you cannot really pick a bad infant seat. There are very very few infant seats which do poorly in independent safety testing and where there are, they tend to get recalled and taken off the market ASAP. So don't overthink the infant seat choice. Save your money and energy for researching the next stage up because here there is really a huge range of safety from potential death-trap (and somehow they don't get taken off the market) to seats that have passed incredibly stringent testing.
Safety wise for infant seats if you want to go above and beyond, look at side impact protection scores as that is where the differences lie.
It's personal preference whether you want a car seat that goes onto the buggy or not. I do find it's useful to have one you can carry around, because they tend to fall asleep in the car and it's very, very nice to be able to transport them still sleeping for as long as you can! Bear in mind this does carry some risks, however, IME, if you can't carry them around in the car seat most people end up sitting in the car to allow naps to finish anyway which is exactly the same thing! So you might as well be in your home letting them finish that nap.