Perhaps you can find a Trackmaster crossing, built-up or kit. These show up on ebay.
This is a 60° crossing but they can ge had in 90° an 45°. You could take the pieces and rebuild it to fit your needs,
You could cut the approaches to an Atlas crossing if it fits your angle needs.
How high is your layout going to be? I saw one that was high enough that the hood of a truck would fit underneath when parked in the garage. The layout was fixed permanently unlike others which would be lowered via ropes when the car was out of the garage,
Jan
