About a year ago TNT was showing Se7en just about every other weekend, it was cut for TV but that film didn't have that much language to delete, mostly one scene was all they did.
I just checked my Directv online guide and Se7en is not listed in search, which includes the next two weeks, and I've got all the HBO, Cinemax, Starz and Showtimes channels as well as others in the Premier Package.
I checked Bestbuy and they don't list it either. Walmart I checked next and they have the widescreen Blueray DVD for $7.50 and they say it's in stock at the 466 Walmart. Unfortunately when it comes to Memento, Walmart only lists it available as part of the Christopher Nolan Blueray Collection which also includes 3 Batman films, Inception and Memento for $43, they do show it in stock at The Villages Walmart.
Personally I've seen Se7en so many times I've lost track, I did get the DVD a while back for like $5, I think it was in one of those bins at Walmart, it wasn't the Blueray. Memento I've only seen on TV, not in DVD, it's well worth seeing multiple times. I've seen it only it about 3 times because it will give your brain a test.
Next I search Netflix, they list both titles available on DVD but neither is available for streaming. I also check Amazon, you can watch Se7en for $3.99, you have 30 days to watch once you've purchased. Memento they show is not available.