I got a JustJap kit for my R34 - awesome kit for the money (and fyi someone else is selling what look to be identical kits on Ebay now for $400) .... was an absolute bastard to fit - had to fabricate all of the mounts. Not an entirely hard job to do, but lots and lots and lots of mucking around. Not sure if the R32 kit will fit better or not?
I didn't get ANY extra lag whatsoever, maybe you did something wrong bbe? That said, my R34 does still have the factory nylon impeller, which is supposed to be pretty much lag-free.
But anyhow, the hard bits are:
1. the positioning of the hole you are going to cut under the battery (I bought a hole-saw but it was useless - wouldn't cut). Ended up drilling about 40 small holes in a cricle and punching the centre out - not a fun job. You just need to work out roughly where you think the hole needs to go and do it. Remember to fit the intercooler first, as that is the solid part you need to line the pipe up with.
2. positioning of the cooler is actually quite easy - you just need to sit it in a nice spot, then drill a hole that lines up near each mount point, then make a bracket to suit for each of the 4 points.
3. as for the bumper bar, fit the cooler and pipework completely up, then try to fit the front bar. Have a look where it hits the cooler, then mark a line on the inside of the bar where you need to cut. We used an angle grinder (careful of molten plastic on your legs!), but I would recommend a smalll ban saw or similar.
4. the pipework is a litle tricky to figure out - you need to use some of the stock pipework so don't pulll it all out.
Good luck!