tight budget strobe flashing
great. looks like the flashes for me
since i am using them for a samsung and off camera only, does it matter which i take ( canon or nikon?)
No. What is important is that these flashes already have a built in optical slave. All you need is to use the built-in flash of your camera to set them off. Be sure you can use manual power control of the built-in flash, any TTL type setting on your camera may interfere.
You can use the built-in flash at a low power setting indoors. Try 1/16th of full power. If it works, great, if not then try 1/8th, etc. At 1/32nd or 1/16th of full power the built-in flash won't contribute much light to the image but you may see a faint highlight from the camera flash.
Of course you can use the built-in flash as a fill light too. Just play with the power settings of your flash units and the built-in flash to get a pleasing ratio.