A good approach to Gilmour, is Reverb, Delay, and Phaser, one of the best and simple to use is the MXR Phase 90 Script model (not the BLOCK edition which is more "modern" sounding) the Script have a more 70's sound and is more mellow, it can even do a good "leslie" type of tone...
I play this setup through a boutique amp (Fender style), and a Marshall Class 5 (kind of a mini Bluesbreaker amp) and both can give good Gilmour like tone... well, in the ballpark, because the real setup would require me to sell the house... ;-)

Had several MultiFX over the years, one of the best I've used is the Digidesign Eleven Rack, but I still prefer the analog approach with stompboxs.