Either will work ok, but if you use the plastic drains, make sure to pour a pad of concrete under it before pouring the floor. If it's sitting on dirt or gravel before you pour the floor, it will look great when finished, but will move/settle over time, especially if it's located where you will run over it with tires.
This comes from experience when I finished my first garage. On my second garage, I decided to fore go drains altogether. I sloped the floor towards the O/H doors. It eliminates the mess of cleaning out the drains, I don't lose small parts in them, I don't have to worry about rolling toolboxes, tool carts, transmission jacks, oil drains, etc., over them, and it eliminates the smell and cold drafts coming through the drains in the wintertime.
Good luck with whatever you choose to do.
Dale
