It's Mamas & Papas, which use Cybex, so any brand that uses the same adapters will work, this is the current list:
Joie (except Juva)
Cybex
Maxi Cosi
Nuna
Avionaut
Besafe
The new Britax 2021+ models - Babysafe 3 / i-sense / Babysafe 5Z2 - older models (Babysafe 2, original Babysafe) won't work here.
When looking for a car seat to go on a pram only the infant carrier models (to approx 12/15 months) work. The ones up to 4/7/12 years don't work.
You can take the pram (with car seat adapters) to a car seat shop and try out the fit before you buy as it's not always a 100% guarantee, but these are at least the correct adapter type.
In terms of views of the brands:-
Joie are a bit scrunched up but good for budget-friendly models. The i-Level is the most popular. I probably wouldn't bother with the Gemm models unless you're on a vv tight budget and unfussy about the seat. i-Snug is a good budget buy.
Maxi Cosi are all flawless to use and lovely seats, but can be pricey and most of their seats are 75cm limit, which can be frustrating if you've paid out loads of money and then have a really long baby!
Cybex have some gold standard lovely seats but ££££. However they also have some really excellent, lesser-known, budget options which I rate highly. My guess is Cybex will be very likely to work with your buggy as they are associated brands.
Nuna have some good lightweight ones but people seem to either love or hate the fit for newborns. The sunshade on them is fantastic.
Avionaut are a lesser known brand but really unique, innovative seats. They have a lie flat boost insert for newborns which works really well, better than pretty much any other seat, and they are incredibly light due to being made out of EPS foam rather than having a hard plastic shell. They are really nice seats, would def recommend looking at if you can find a stockist.
Besafe have one of the cheapest modular bases, meant to be back-friendly and excellent safety record, but again short height limit and they are less widely stocked.
Britax seats are really well designed and nice to fit with belt as well as with base. You can get an angle adjust base to adapt to sloped vehicle seats.
You don't NEED a modular base/rotating base. The rotate is a bit of a gimmick with infant seats as you usually get them in/out of the seat in the house, not the car so not restricted by angle. Be careful that you don't end up overpaying for a base that you won't continue to use - the majority of toddler seats don't need a separate isofix base (as you may already know from your DS!) and the seats which click into these bases commonly cost £300ish - so you don't really save any money.
Most people do like the convenience of a fixed isofix base. For more basic infant car seat models you can often get a matching base for about £100-150. Sometimes you get a bundle with car seat + base all in - shop around as it is sometimes cheaper to buy them separately, just make sure you're 100% sure that the base + seat you buy are compatible if you buy from different places, as most shops are reluctant to refund anything car seat related for safety reasons.