First, it's amazing to me (and quite an achievement) that you've managed to reach Legend tier with a 61.72 avg in less than 2 1/2 months since joining in July, and with only 153 ranked rounds (I'm assuming you must play a TON of coin games or win a lot of monthly/weekly tournaments?). Then add in it's been with starter driver/irons/balls, it even more impressive.
Second, as said above by others, if you can handle the meter speeds of the L90s they are great clubs. I've been using those same clubs for most of the last 6 months or so and could still be using them today if I really wanted to, but just in the last week or so have "upgraded" to L96 driver and L97 irons. (The only reason I did so now was the meter speeds, but since getting them I do tend to think the forgiveness/precision is way better than the stats suggest when compared to the L90s).
Third, for balls I'd also do as suggested and start out with "mid-range" ball (L33-L61) for a while and tune in on the specs you like best distance/spin wise. You may find one with more distance than spin meshes with the new clubs better, or it could be the other way around for you. If you've been playing primarily with the starter rock, you'll find the balls can make a world of difference. One I really liked with the L90s was the L34 Callaway - it has a slow-ish meter which helps slow down the driver/irons and has 4 to 2.5 distance to spin ratio which was perfect for me with the higher spinning irons. Once you figure out what ratio you prefer then you can start experimenting with the "high-end" balls that have a similar ratio.
Just my thoughts, but then again with your stats and earnings compared to mine, I should probably be asking you advice, lol.