Need advice: DIY speaker cable??

[paramex]

Hi all, I'm looking to make 2 pairs of speaker cables to connect 2 pairs of speakers (2 stage monitor and 2 mains, all passive) to a power amp/mixer combo. The mains, 15" speakers are rated 300W and the stage monitors are small 10" rated 60W. The power amp is rated 2x300W @ 4 ohm

So, I planning to buy bulk cable and make the speaker cables myself.
I'm looking at this cable from monoprice:

For only $23.01 each when QTY 50+ purchased - 12AWG CL2 Rated 2-Conductor Loud Speaker Cable - 100ft (For In-Wall Installation) | 12AWG Loud Speaker Cable

I'm not sure if this speaker wire can be used for live sound since they're not put under professional audio category. I couldn't find any speaker cables under that category at monoprice, only instrument cables.

So yeah basically my questions are:
- is it ok to use those cables for live sound use? If not can someone reccomend me where to buy cheap but quality bulk cable?
- is it ok to make the cables in different length (L and R?), cuz I'm thinking the mixer will be located on either the left or right side of the stage so it may be more economical to make them like that (since I'm buying bulk cable :D)

Thank you in advance!!