Hair extension course and suppliers

Hi, I recently booked a course to further my confidence in hair extensions with the London Hair academy :( to my luck on the day i turned up, i found out they had gone bankrupt - asides from that drama of taking all the time off work and paying for it, I am now about to complete another course with Bella academy and cant wait. However, the whole thing has put me on the back foot and my main dilemma now is looking for a good supplier in the UK that doesnt mat or go frizzy, does anyone have any reccomendations? Also, I wanted to know the most popular type of extension currently? I used to have Fusion bonds, but would never go again.