I am aware that a couple who are both Singapore Permanent Residents are eligible to buy a resale HDB flat in Singapore. Is this the only available option for an SPR couple, or are they eligible to buy other types of flats?
According to HDB, the eligibility criteria for a new flat in respect to citizenship is:
This holds true for all the categories, you can check this by clicking through the categories on the left hand menu on the website.
Note that even for resale flats there is a restriction:
This might be a concern for you if you only plan to acquire PR status.