When I have AA or KK UTG, i got to slow play or all in preflop? Table 9 players
It isn't just a "slow play or allin pre" situation. You have more than two options.
Honestly, at micro/low MTT's and SNG's, I very rarely advocate slow-playing anything... Especially since an UTG limp is such a weak and weird play, you're starting off by alerting players that something may be amiss with you.
I generally make my standard open raise, which depends on what I've been doing all tournament (2.5, 3 or 4 times the BB.) If you are altering how much you open-raise with depending on the strength of your hand, alert players WILL pick up on that. Don't let them pigeonhole you by doing that. My general rule of thumb is raising 3x the BB, and adding an extra BB for any one who limps in front of me.
Obviously, if your M-ratio is fitting, then shoving KK or AA is the easiest of shoves. Hell, there will be times I'll open-shove AA UTG just to look fishy, no matter what my M-ratio is.
I pretty much never advocate the "limp and hope for a raiser to reraise." In a lot of cases, people will just limp behind you and then you wind up with 4 other players getting shocks to crack your premium KK or AA.
In essence, I don't get cute with KK or AA. Play them strongly and punish draws if you are overpair to the flop.
(EDIT: BEWARE paired boards, as always.)