I definitely agree on the arrangement, it's fantastic.
If you want some more realistic picked guitar stuff (I'm sure the GarageBand guitars, or any non-sample library guitars, aren't as realistic as, for example, some sort of a Kontakt guitar library), I can do it and send you back a WAV or MP3 if you send me a MIDI of the guitar track (for the greatest accuracy). I'm sure it's possible considering you're using FL Studio (and I am too).
I have Keolab Spicy Guitar (acoustic guitar, free), this Kontakt lead guitar library ($179.99) and Shreddage Rhythm Guitar library ($50 or $70, depending on the deal you are looking at). Orangeholic is like the best sound demo for what you're looking for, btw, for Strawberry Evolution Electric Guitar.
Oh, and I have a lot of other stuff, so if you want to collaborate, I'm willing. I can add lots of cool stuff, like better drums, brass, lush pads, bells, etc.