The 15kg Rocna is perfect for that boat if your waters are anything like the East coast of the US.
Like yours, my 1977 GB 32 came with no windlass, but a 33lb Bruce. The first improvement I made was a windlass (Simpson Lawrence), proper bow roller and a 15kg Rocna with 30' of chain and lots of nylon after that.
This held us perfectly for 1200 miles of the ICW and cruising on the Chesapeake. If you want to spring for a higher quality windlass you can, of course, but so far, so good for us. The Rocna is as good as the Max I had on my previous boat, a 33-foot sailboat, and better than a Bruce or Delta. That's high praise.
In 55+ years of cruising, I have come to dislike Danforth type anchors. They hold beautifully until the current or wind changes in the middle of the night. Then, you're off to sea (or shore) again.
-- Tom