First of all, I would just like to point out that the ability to slide a wheel is relative and depends on many factors, e.g. what wheels you learned to slide on, your trucks, the type of deck you have, type of road pavement, steepness of the hill, and technique etc. For example, my brother has an Earthwing Supermodel (drop-thru), Paris 180’s, and Metro Motions. I have a Topmounted Clutch Jailbait, Indy’s, and Cult Classics. To my brother, my setup is way too slidey and uncontrollable. However for me, it’s just right. He loves his setup, and I think it’s harder to slide than my setup.  

That being said, and assuming you and your friend have relatively similar decks and trucks, I would probably recommend a wheel in the freeride shape with a duro of about 80a. The freeride shape will give a nicer grip/slip point, and the 80ish duro will keep the slides relatively controllable. Some wheels that fit that criteria would be: Cult Classics (I have a bias toward these wheels), 78a or 80a Metro Motions, 70mm 81a Round Lipped Sector9 Race Formulas, Venom Sidewinders, Abec11 81a Freerides, and Abec11 81a Flashbacks. There are tons of options out there.

One thing to keep in mind though is that once you do find a wheel you like, stick with them and learn on them. All freeride wheels are relatively the same. Technique has a bigger impact on how “smooth” or “slidey” you’re wheels are. If you switch wheels often, you will have a transition period to get used to the new set of wheels, and it will take time before you’re able to do every single slide again.

Hope this helps a bit. Now get off the computer and skate!