Who makes the best hi-steer kit? Does anybody offer one that replaces the stock steering arms instead of piggy-backing on top of the stockers? I guess thats not too important, just would look cleaner. I plan on running a 2.5" backspace wheel, which most seem to require. Oh yeah, this is for a Samurai with Suzuki axles and a Trail Tough YJ spring/Missing Link setup.

If running a stock or Kick P/S box, then I would strongly suggest using the Calmini H-Steer.  Moly arms that tie into the stock mounts and caliper mounts.  This provides 2 planes of attachment, both in strong locations.  This is the only system that does this.  Stay away from a system that mounts only to the king pin, as this is a weak design and could cause the pin bolts to sheer.  Also, the Ackerman angles are very close to stock, which means steering is very precise and correct.  With Kick P/S, it's easy to turn 33"s in the rocks.

It's also very well priced compared to most.  You will need min. 2.5" of BS to run this set up (needed to make the TRE locations in the correct position to obtain proper acks.  to learn more about this, and how many hi-steers (like Benx arms) do not take this into consideration, follow this link for more info

http://autorepair.about.com/gi/dynamic/offsite.htm?site=http://www.rctek.com/handling/ackerman%5Fsteering%5Fprinciple.html

My 2 cents.

There are a couple of nice kits out there, I think Low Range Off Road offers most of them.  Or you can go cheap and just pick up some steering arms from an old Mercadies.  There was someone selling a few pairs in the For Sale section.

On the Sammy axles, pretty much all the high steer kits connect to the calipers, not to the stock steering arm.  If you wanted to you could probably just cut the original arms off.

you could look at trailtoughs highsteer or sky manufacturing.
I use sky's and it bolts up to the caliper bolts you can get it for both sides.
www.sky-manufacturing.com