Omaha Steaks has good sirloins for the price, good to keep a few of those badboys in your freezer and just cook em up when ready, as they come already frozen.
If it's your mom's bday, you want some fresh, USDA Prime filets.
USDA Prime is just a grade of meat, the main thing is the marbling(fat content) to make the meat nice and tender and juicy. That is what is served at high end steakhouses.
USDA Select
USDA Choice
Angus Beef is usually a grade of choice in my experience.
USDA Prime
American Kobe Beef
true japanese wagyu beef
As far as i know, those are in order of worst to best. I've only had true wagyu once and it was wayyyyyyyyyyyyyyy too rare for my taste, it was barely even seared.
Then you can get into aging, which also can improve the meat...there is dry aging and wet aging. but that is a whole different discussion
Yeah man, the USDA Prime ive seen at Central market is like 25-28 a pound.
get each person an 8-9 oz Filet, i like mine 2 inches thick.
Also, be careful cooking them up man, especially if you've never cooked them before.
My preferred method is to sear them for 2 minutes on each side on MEDIUM HIGH on your skillet, pref in a stainless steel or cast iron rig.
Then throw them in the oven....for 2 inchers, ive found that between 8-10 minutes will give you Medium/Medium Rare
Then remove them from the oven, top with a pat of butter, and wrap them up in foil and let them sit for another 8-10 minutes.
This part is absolutely crucial..if you don't do this, and just serve them right away, when you cut into the meat, all the juices will just pour out all over the plate.
careful with them, ask for advice from some other Chefs here...there are some really good chefs on this site.