Design/blueprints for a dropin and what to put on top/where to get it?

Pretty sure at 10 feet you will want something like a wider supporting base, anchors, or make the platform larger so that it doesn't fall over. Every thick line on the grid is equal to one foot, so if you print it out you can measure exactly how long each piece of wood needs to be quite accurately. For building refer to the sticky where the kid make a 6 foot tall drop in, building principles and supports all apply to this build. For turf look at places like home depot, if you are in Canada it is likely that they don't have any so check out carpet stores- if the carpet stores don't have any they can order it (but it is expensive) the cheapest thing to do is to buy 2 pieces of plastic lattice for the drop and carpet the exposed transition and jump in astro turf. And yes you better have a long ass rail as you will probably have insane amounts of speed with this set up.

Also I just realized that the main tower is off on measurements, it's 2.5 feet across not 5, looking at my redesign 4-5 feet should be structurally sound. I have mine at 8 feet by 4 and with the ramp attached it doesn't move.