A good idea would be to pick out the spades first by getting a few to sample. Check them out on your speakers binding posts and then either crimp or solder them onto the ends.
Crimping should be good enough. thereafter, or prior to the spade attachment, slip some heat shrink onto the cables so the oxidation where the connectors are attached is impeded.
It comes in sizes and colors so you can tag each end as to polarity. Putting a slight twist to the pairs and adding some 1/4 inch sensing tape now and then to the length of the cables should also make them more manageable and neater in appearance. Sensing tape comes in several colors.
I hear there are socks for DIY speaker cables too... somewhere online.
If the project doesn't work out satisfactorily for you, simply add plugs to either end and you'll have that high current extension cable or power cord, you've always wanted! lol