I get my baits in lots off ebay!
Any pony you own is yours to do with as you wish!
You will find a lot of debate here over what pony you can an cannot bait, but it all boils down to the fact. its yours. you can do what you like!!
I look forward to seeing your work!!
If you are just working with common G3's, theres plenty about, and all the G4 range, that's easily available.
But G1's there will always be debate over! But some G1's just are not restoreable, therefore creating something new from it, gives it a new life. a lot better than chucking it in the bin!