I opened up a 98 sidekick front and a 88 Sammy front expecting the same diff carrier.  Much different.  The Sidekick has an open frame carrier and the Sammy is totally enclosed - it looks a lot like a detroit.  Can't see the side gears, spiders, etc.

So the question is, will a sidekick loc right locker fit in the Sammy carrier.  Hard to believe it will stuff in there!

Is one carrier better than the other?

Yes, the lockers interchange.

If I have both, any opinions on which I should use?

I prefer the samurai one.

If I have both, any opinions on which I should use?

Samurai carriers are Three pin (one cross pin and two half pins).  Kicker front carriers are One pin (just use the single cross pin).  The Samurai carriers are better.  If you use the Samurai carrier with 5.12 gears you will need to get a can (round metal cylinder) to hold the half pins in place.  The lower gears that the Samurai normally use are physically taller and will keep the half pins in place.  ZW vendors will have these cans.
If you are installing a locker you will need the Sammi carrier, unless you get a locker specially for the Kicker single pin carrier (I believe they make them now).

That was useful!  I am building up a new set of axles from parts of three rigs. Gears, lockers, carriers, axles, brakes etc. So help is good.