I would personally never use a heavy organic based soil to plant grass in. When designing golf greens organic matter is held to a very very low percentage of the over all make up of the green.

Saying all of that I would go with the sand based. It most likely fits what you currently have in your yard, soil type wise. You want to try and avoid mixing layers. If you buy sod that is muck based, and then plant on sand, you would see drainage issues.

Example: It rains very heavily, the muck soil allows the water to run through it very quickly as it is already full of water, but then the water hits the sand layer, and starts to pool on top of that layer as more and more water comes down. You now have a bigger problem that can lead to costly fixes.

Long story short I would go sand.

Bentgrass sod, for putting greens,can be purchased with no soil on it at all. They wash the soil off. Probably not available in your case, but intresting none the less.

The other thing you could do is a test plot. Buy scraps from both places and prep a small area of lawn. Plant them both and grow them in as you would a regular lawn. Look back in a couple of weeks. See which one looks better, has denser roots and is generally heathier. There may not be a difference, or there could be a clear choice.