Two Plus Two Older Archives - odds and playing jacks

First off:
- can anyone get me the odds for Jacks vs A4s preflop?

Secondly:
Your sitting with jacks in an MTT with 6 players left, but only 5 get prizes. There are high blinds (10k/20k) and two players at the table have less than 40k in chips. You are second in chips and come in for a raise to 50.000. It folds to the chipleader who raises to 100.000. It gets round to you now, what would you do?

In the situation i was the chipleader and my opponent raised me to 150.000 (having 70k left after that) and i raised him all in, where after he called. An ace fell on the the flop and i won. I realize that i was behind on it, but i believe that i was getting odds to make this raise because there was 280.000 in the pot (250k bets, 30k blinds) and it was another 120k to raise.. so i was getting a little better than 2/1 on my money which i think my odds justify. Its a marginal situation i know, but sklansky teaches that on the bubble you should not play marginal hands if there is someone close to going out. And playing jacks vs a guy who reraises and then reraises you all in after you reraise him is telling you he got at least an ace. The guy cost himself 250$(5th prize) and i went on to win. Even if i had lost i would have been almost sure to get at least 250$ just by folding my way to 5th.

Some of my countrymen thinks i shouldnt have played the hand when re reraised me, but i had him on Jacks or lower because he didnt go all-in after my raise but only reraised me another 50k. Is that a mistake? In the hand i only feared one hand, which was the rockets, and the chances of him having them was close to none in that hand i thought.

Its important to note that when im chiplead i tend to play even marginal hands because i play to win, and not to get money. And in a bubble situation, being the chipleader i was fairly certain i could push him off some big hands.

Thoughts?