Compatible RAM options?

Greetings.
I’m looking for some guidance from the more seasoned hardware enthusiasts regarding RAM compatibility. I’m currently working with a Dell Latitude motherboard and—to put it mildly—my experience with memory upgrades has been less than stellar; I’ve already been sold "compatible" sticks twice by retailers, only to have them fail to post. My ideal setup would be a pair of 4GB modules clocked at 1333 MHz. Does anyone here know which specific modules are guaranteed to work with this board? Ideally, I’d like to source them locally here in the States.
Thanks in advance!

Unfortunately, nobody can give you a 100% guarantee on this—it’s honestly a bit of a lottery. I’ve actually had to return RAM sticks to Best Buy a couple of times before because, even though the speeds and latencies matched perfectly, they just wouldn't play nice together. Your best bet is to buy them as a matched kit if you can. If that's not an option, maybe try to test the new stick with your current setup before you fully commit to the purchase?

p.s. Wait, did I just read correctly that you don't actually have any RAM yet? So the headache only starts once you actually buy it, right? That changes things a bit... Based on your motherboard's specs, it supports DDR3 1066/1333/1600*/1800*/2000*/2133*

So, as long as you grab some DDR3 memory, you should be good to go..

Here, check this one out..