If you want DG’s tone you have to have DG’s gear, or as close to it as possible. GFS won’t get you there. If you’re looking for DSOT/MLOR/Division Bell/ Pulse era tone then there’s an easy solution from EMG, the DG-20 loaded pickguard. Drop it in and there you go. Otherwise if you want the Black Strat sound (circa everything before and after), David uses an SSL-5 (technically a custom overwound SSL-1 but became the SSL-5) by Seymour Duncan in the Bridge position, a Fender CS 69 in the Middle position and a Fender CS Fat 50’s in the neck. There’s no cheap solution and hence why it is the frankenstein guitar that it is.
Other hardware? Start by getting yourself a HiWatt head and some WEM cabinets with vintage Fane purple backs. Oh yeah and a Yamaha RA-200 leslie copy.
As far as pedals are concerned, that all depends on what era you want. If you’re going all out, an EHX Big Muff (Ram’s Head only no current copies), Colorsound Powerboost, BK Butler Tube Driver, EHX Electric Mistress, EHX Small Stone, compressor of your choice (DG uses a Demeter Compulator and in the past a Boss CS-2 and an MXR Dynacomp), Wah pedal, Analogman Sun Face with a BC108 Si transistor and a good delay (David’s using a T-Rex Replica at the moment). Also anything by Pete Cornish would work since DG uses a lot of his stuff. Bear in mind Pete’s pedals are over $1K! Not a cheap venture but that should cover most of the years.
Since you’re looking at GFS stuff I’ll assume you’re not able to commit several thousands of dollars to get that sound. There are some alternatives, but you won’t get HIS tone. Any questions?