I'm not sure if there are many let alone any level 8 and talent 20 drivers out there. If you do find one they will be terrible in all their other attributes and will take many months to train. You should wait and level up (around level 15) before looking for rare and expensive talent 20 drivers. Finding competitive drivers is something you should do once you have reached elite and have all your HQ (excluding hospitality) above level 15 imo...
you can see the difference even at low level... one of my league has 2 drivers 20 talent at level 8 and win every single race with at least 20 seconds of advantage... and the stats of those drivers are so low but talent work as multiply modificator so he win always