in protected waters with winds less than 30 kts a 35 lb Rocna Vulcan, Spade or similar will work well with your bow roller which won't work with an anchor with a hoop. In heavier winds go up to 55 lbs.
Based on traditional anchor sizing (Dela, Bruce, CQR), you'll see a lot of 35lb anchors on a 350/390. We use a Rocna Vulcan 20Kg (44lbs) with 5/16" G40 chain (Which is what the Rocna sizing guide calls for. Note that they claim to 'oversize' to begin with). I suspect your windlass has a 5/16" gypsy.
We have about 130-ish feet of chain and about 125-150 ft of 3-strand nylon 5/8".
The short distance from the bow roller to the windlass makes it awkward to use a CQR because of their long shank. The CQR doesn't sit in the roller very well.
on my MS390, I have a 45lb quick set Delta, a swivel, 50 ft of 1/4 ht chain and 200 ft of 1/2" three strand nylon rope.
I also carry a Fortress Marine Anchors FX-37REMAN FX-37 21 lbs wiyh 200ft 1/2" three strand nylon rope as a storm anchor.