With the bow it is not the speed of the arrow but the power it is packing. I think the general speed is around 300 fps (90 m/s). There are some compound bows that can shoot faster with thin diameter arrows.
Usually 55 lbs draw is enough to kill any large game. I shoot a 65 lb take down recurve when I train. ThanThen I switch my bow limbs for 50 when I hunt (also train with it but not as much as with the 65).
If you take look at Hoyt website they have hunters taking down buffaloes with 50 lbs bows.
Also a lot depends on your arrow head and the diameter for the arrow. Thinner diameter penetrates deeper. Quality arrow head will slice up the heart so the animal bleeds out in matter of seconds.
Also it depends what you prefer to shoot. Some guys like longbows because of the feel and raw power. But it takes a long time to master.
Most people shoot recurves because they are easy to start with and are affordable. Also the bow generally does not vibrate as much as a longbow.
ThanThen you have compound bows. I don't like them very much. ToToo much tech and at some point youyou're just better ofoff with a rifle IMHO.
To safely hunt anything you have to know your game. If you go hunting moose that is pissed off at you; well you are asking to have a meeting with the reaper.