JD, are you happy you upgraded the rear suspension first instead of the front or do you feel you should have done it the other way?
I'm in a similar situation, intermediate pace looking to continue getting faster...trying to decide which component I should focus on first. Right now I'm just running re-sprung front and rear stock suspension, with an additional adjustment nut for rear ride height. Haven't necessarily had any issues yet, but I'm guessing as I get faster one piece or the other will reach it's limits.
Item 1) GP Suspension are very, very good, I'd have no hesitation using them. With that said, I had Traxxion Dynamics set up my Penske 8987 triple adjustable shock for two different R1s and was also very happy with their work. I go with GP, because they are on the West Coast, as am I.
Item 2) Now, as to shocks, all OEM with the exception of the R series Triumph Daytona, and top tier Apilia Ducati, MV Agusta are for the most part shite (sans a few Sp. Ed. R1s w/Íhlins). And some might argue, the CBR1000RR SP. But since 2009, reviewers have been lauding the GSX-R 1000 with Showa Big Piston Forks as having fabulous front ends. And the latest incarnation of the ZX-6R with Showa Big Piston Forks have been generally greeted with kind words.
Item 3) Thus, I'd make the initial plunge with a new rear shock: Íhlins, Penske, or K-Tech are all gonna see any rider show credible improvements pretty much out of the gate.
So, from my personal experience, unless you're vying for national ranking in the professional spectrum, I'd have to think long and hard about new forks. But most would see a marked improvement with a fork rebuild. I'd be inclined to go with either GP or Traxxion & save a bit of your own money. And if you are a national top shelf rider, it's not your money any way, and you'll have a small army of suspension specialists who will build up and tear down both ends until you're setting on pole.
Or, if you have really deep pockets, and like sticking chi-chi stickers on your bike, then go for what ever colour of suspension you like best.
At the end of the day you could have the shock and forks of of Marc Marquez's RC213V and do no better than you did with 30K mile suspension, if it is not properly setup. Setup is the keystone.