I have a pair of Nike SP-8 TW shoes that need to have the spikes replaced. Do I need to buy the same Q-Lock spikes that they came with or can I pretty much go with any brand and style of spikes?

any spikes that incorporate a Q-lock design will work..
anything else will not work

Awesome!!! will any spike wrench work?

yessir..
as long as the tool as two prongs extending at the end of it..
side note: the cheap ones work just as good as the expensive ones unless you need the leverage

If you've had the spikes in there a while, or play in a lot of wet and/or sandy conditions, spend the 15 dollars on the more expensive spike wrench. The cheapy ones will snap or bend the prongs when you're trying to add leverage. Wet sand gets under the spike and turns into a mild form of concrete over time and you'll need all the torque and strength you have to take out the spikes.

Note: Twist firmly b but don't be violent when removing the spikes or you'll pop out the node the spike goes into and you'll be SOL.

any recommendations on what wrench to go with? and whether to go with stinger or scorpion spikes? I think these are the main two companies that sell replacement spikes right?

soft spikes too.

forget the wrench(I've tried all sorts) and use a little WD40. Works like a charm on the toughest locked in spikes.

If you go with champs stingers they will last you longer but they dont offer as much traction as soft spikes or black widows do as well when its time to change a stinger theres a black c on the bottom it will rub out to a black looking smudge. Soft spikes and Black widows will lose the prongs pretty quick if you like to walk along cart paths. G' luck in picking and changing a spike.

A little water would do the trick as well. Wet the bottom and let it sit for a few minutes. They should all come out with ease.