Yes, you need a good one. Probably one with a hardened drill guide and using cobalt drill bits is probably a really good idea. Because you're drilling on an angle, it's really easy to break bits. I thought I got mine from a trusted source but it wasn't a good one and I gave up after breaking a few bits. I would expect that my technique probably left a lot to be desired too.
We discussed the issue of the bushings coming apart before. I was very lucky to have found the thread and guess who started it? You, JB!
http://www.lotuseuropa.org/LotusForum/index.php?topic=1709.0I am certain that I had a washer on the outside of all of my bushings but still got delamination (see attached picture). You brought up that there seem to be two styles of bushing and that those whose ends are rolled over a bit work best. It's very possible that the bushings that failed on my car were the "unrolled" (i.e. straight outer tube) and that was my problem but I decided to put a large diameter but thin washer between my bushing and the frame (I posted a picture on the aforementioned thread of the washer installed on my suspension but you have to look VERY carefully to see it) and the problem went away. It could also be that the replacement bushings were of the "rolled" type.
Since it was on the lower A-arm, I figure that either one arm was warped a bit or more likely, the bushing for the bottom of my SPAX shock was a bit smaller than stock and tightening it tended to try to squeeze the inboard end closer together. When I found it, I posted to the yahoo group about it and I had several people say they had the same problem. Thinking about it more now, When assembling the front suspension, I think it make sense to build the lower A-arms with shock and trunnion and put it up to the frame first to see if you should shim around the lower shock mount in case that is a cause.