I think yes, they are reasonably cheap so would only have to help a little in my book to be worth it. Worst case is if it doesn't help at all then take it off and your down $85 plus postage.
What body shape do you have? On my ute I'm going to try running 17s on the front with 18s on the back with a set of 15s for track duties. 18s will required work to you inner and outer guards especially if you try to get a reasonably low ride height.
This place make them - you might have to take them somewhere to get welded or what ever is needed to secure them to your carbs. http://jntperformance.com.au/
I installed a silvia wiper motor in my 1200. One hole had to be drilled out and I cut one leg off the wiper motor. I don't think it is any smaller but it looks a little better and will work with the silvia combo switches I installed. I just need to drill out the 1200 wiper motor arm and put a bit of weld in so that the wipers park in the right spot. http://datsun1200.com/modules/myalbum/photo.php?lid=21779
Sort of comes down to personal preference. I would use LEDs because they last longer. I don't think heat generation would be to much of a problem as they standard lense (well in the ute anyway i think) are plastic. With the leds you might have to buy some other bit (can't remember what they are called) which corrector the rate the indicator flashers due to the decrease amp draw.