If the shop's selling them "for off-road use only" then you can bet they're not legal for road use, otherwise you should be fine with them.
Narva isn't a bad brand - they may not be up to the standard of Lightforce lights, but they won't be shabby. If those lights appeal to you and your pocket doesn't object then I wouldn't say no.
Plenty of opinion already in these forums on the type of lights to use. Personally I have a spot on the right for distance and a flood on the left for area viewing. I don't have enough light on tight forest trails at night, so I'm looking at running lights as well (we discussed this when we met at The Rock, but needs to be said here too for the other readers' benefit).
Out on the outback highways there was an advantage in having the spot beam, and being able to see a kilometre ahead. If you only intend to do forest and close work, maybe a pair of floods would suit you better. If you angle them out just a little, maybe you'll also cover the ground around the front of the vehicle and resolve the issue I have in the forests where I've got blackness just around those tight bends.
The law states you can have a maximum of 6 lights up front. You could go a pair of high power in a spot/flood mix, and a pair of lower power floods for close range stuff. It all depends on what you want to do. Your alternator could certainly handle it, so there's no need to worry about the electrical side of things.