Reddit reviews Suncentech Bike Stem 31.8 Bicycle Stem Handlebar Riser Extender for Road Bike, Mountain Bike, MTB, BMX, Fixed Gear Bike (Only Fit 1.25"/31.8mm Handlebar) (45° (31.8x90mm))
We found 2 Reddit comments about Suncentech Bike Stem 31.8 Bicycle Stem Handlebar Riser Extender for Road Bike, Mountain Bike, MTB, BMX, Fixed Gear Bike (Only Fit 1.25"/31.8mm Handlebar) (45° (31.8x90mm)). Here are the top ones, ranked by their Reddit score.
★ Only Fit For Handlebar Diameter 31.8mm (1-1/4"), Steerer Tube Diameter: 28.6mm (1-1/8"). Please read Purchase Guidelines carefully before order.★ Degree & Length: 25° & 70mm / 35° & 90mm / 45° & 90mm Optional★ Constructed of high-strength CNC machined 6061 T6 aluminum alloy.★ Easy to install, just connect up the original front fork tube. Four bolt bar clamp holds handlebar securely.★ Suitable for most MTB mountain bikes, road bike, fixed gear bicycle, BMX etc. Best choice for cyclists, DIY upgrade the bike for more comfortable ride.
While that would work it's not very elegant.
I suggest you start by flipping the stem to angle upwards would increase the handlebar height by about 2.5cm. If that's still not enough, you could try a stem like this.
Something like this might bring it up a little further. It's a 90mm long 45 degree angle stem.
https://www.amazon.com/Aluminum-Mountain-Handlebar-Extender-Components/dp/B075XJJ4CJ/ref=sr_1_12?ie=UTF8&qid=1506605322&sr=8-12&keywords=31.8%2Briser&th=1&psc=1
Combine it with something like this and it would get even higher.
https://www.universalcycles.com/shopping/product_details.php?id=51573
5.5" rise 31.8mm clamp bars
https://www.amazon.com/Cycle-Group-BX-HB1331855-BK-Maximus-Handle/dp/B00B90HCKQ/ref=sr_1_1?ie=UTF8&qid=1506606474&sr=8-1&keywords=BX-HB1331855-BK&th=1&psc=1
Another issue you're going to run into is cable length. The cable on your left hand brake looks like it's just long enough to fit the current height. If you push it up with new bars you're going to need a new cable. With a 5" rise I'd be willing to bet you're going to need all new cables. Unless you can do it yourself you may want to sell your bike and buy a Roll like your friends. That's going to get expensive if a shop is doing it.
Edit: https://www.amazon.com/Delta-Cycle-Alloy-Bicycle-Raiser/dp/B000FGYKWS/ A stem riser might help get your existing bars up higher.