For the sake of argument, let's say the United Kingdom of the Netherlands (OTL Netherlands and Belgium) survives to this day. What's the likelihood of keeping Suriname part of the country, similar to how New Caledonia is part of France, and elects representatives to the national parliament? How could that be brought about?
OTL there already was a pretty big chance of Surinam remaining part of the Netherlands. Surinam was basicly forced into independence by the Dutch anti-colonial government. I doubt a majority of the people living in Surinam were pro-independence as more than 1/3 of the people living there moved to the Netherlands just before independence. I don't think it realy matters wether Belgian had remained Dutch or not. You just need a Dutch government that doesn't want to force the issue and Surinam is about as likely to become independent as the Dutch Antilles, who still are Dutch and in general want to remain Dutch (although Curacao might want to become independent, but we'll await the result of the possible referendum).
So Surinam remaining Dutch is actualy quite likely. The problem is Surinam electing representatives. Until very recently the Dutch Antilles did not chose any of the members of the Dutch parliament. They were part of the kingdom of the Netherlands, but not of the Netherlands itself. Basicly the kingdom of the Netherlands is a federation consisting out of the Netherlands, Aruba and currently Curacao and St Maarten (both Curacao and St Maarten were until recently part of the country of the Dutch Antilles together with Bonaire, St Eustatius and Saba). So neither Aruba, Curacao and St Maarten chooses members of the Dutch parliament. Bonaire, St Eustatius and Saba are now part of the Netherlands and actualy do vote for members in the Dutch parliament (although their vote barely matters as they have very few inhabitants).
So if you want Surinam to remain part of the Netherlands and be able vote for representatives in the Dutch parliament you need to change two things, avoid independence (relatively easy), avoid the current federal state of the Netherlands. The last part should be relatively easy, as you have a POD in the early 19th century and you need some changes to the Dutch constitution anyway to keep Belgium within the Netherlands.