You shouldn’t go far wrong with the Marantz PM6007, I am not familiar with that exact model but have an older version of a similar level and love it. Loudspeakers are a very personal choice, if you can listen before you buy its best, but remember your room will sound different.
The Monitor Audio are famously unforgiving of poor placement, but work well with lower powered amps. So you have a plus and a minus there. If you do have some placement issues, you may be able to compensate to some degree with some room treatments (but that’s a whole other rabbit hole!!!).
If you are looking on ebay you need to be patient and sensible. Some people over pay. You may get lucky and find a “collect only” listing near you. Collection only nearly always sell for less. I picked up pair of nearly new Q Acoustics 2020i (that I used as reave AV speakers) for £35 back when they were £150 new. Other were selling over £100 + postage. The other advantage of buying second hand, if you buy a decent brand for the right price you should be able to re-sell for a similar price in future.
A leftfield suggestion for speakers Mission 701 (or 702, the floor-standing sibling). They stopped making them about 20 years ago so they will be old. You used to be able to pick them up for next to nothing, but I think they have gone up in price. If they ever go wrong all the components are available to replace. The only issue with Mission speakers of that generation is the glue on the baffles can dry out causing rattle. This is easily fixed. They sound fantastic should pair well with your amp and are front ported, very forgiving of placement. The only warning they are large units.