What aftermath said. If you don't go ape-wild, your scores might well be back where they started as early as the second or third month. If you get an AmEx, they frequently don't even show up on your reports for several months, showing the opening date, so you might not see a dip at all. Some people's scores grow from the get-go, because their particular credit profiles "needed" another revolving account.
With the cards you're looking at, it's worth paying to pull your EX FICO score. (First Google fico discount code coupon to get a code for at least 15%.) Probably it's within 15 points or so of your EQ, but you never know. Some are way different.
As long as your EX is 710-720 or above, and you have no collections, BK's, unpaid charge-offs, or baddies within the last two years, you should be fine. I wouldn't worry about land mines. If you want an AmEx credit card (the Blues, HHonors, etc.), do a lot of research to decide the best deal. For instance, Blue Cash can be great if you run a huge amount of money through it every year; otherwise it's pretty eh.
If you'd rather the inq be pulled from your EQ report (for whatever reason), take a look at Citi or Chase, although both of them are pretty variable as to which CRA they pull. The reason that you got so much feedback about PenFed is that they're an EQ puller, and that's the one you listed.
And finally, if you're working your credit right, you won't care about the APR, because you won't be carrying balances anyway! The only balance I carry on a card is a 0% BT card, and I'm paying it down $250 every two weeks. CCC's don't get a penny of my money.
* Credit is a wonderful servant, but a terrible master. * Who's the boss --you or your credit?
FICO's: EQ 781 - TU 793 - EX 779 (from PSECU) - Done credit hunting; having fun with credit gardening. - EQ 590 on 5/14/2007