If you use the advanced search you should get tons of info on this topic.
I agree with Terry not to go too big to start, make it fun first. Juby B. will tell you right size for your

, we have an

with shorter mast so might be different size spinnaker(s).
I think the definitions may be a little different depending on the manufacturer, some may be different names for similar type sail.
My general interpretation is:
Most "light-air" spinnakers are made of about 1/2-3/4 inch rip-stop nylon.
1) Symmetrical = both luff and leech are equal length (we use a double-jaw spinnaker pole)
2) Asymmetrical = Luff is longer than leech (no pole required, but we have a single-jaw & spike-end whisker pole and parrel-beads)
3) Gennaker = Luff is longer than leech (similar to an Asym) but flatter cut like a genoa.
* We also have adjustable tack line led to cockpit, sheets led to aft blocks near stern cleats, topping-lift and down-haul lines, and dedicated spinnaker mast hound and halyard.
We have all three types of spinnakers with separate Chute-Scoops (photos below).
Our Gennaker: (can point a little higher than a our Asymmetrical, basically a similar cut (shape & draft) as the our dacron 150% genoa)
Our more balloony Asymmetrical
Our strictly downwind Symmetrical (with pole to starboard, you can see the topping lift bridles black line)
