SRP is a very good polish. EDS is, in my opinion, so much better for newer cars. If anyone has a black car, you can really see the difference.
You can use all three AG products mentioned together. SRP, then EDS followed by UGP. I have used all three at length and still used them.
Only thing with AG polishes, is they contain silicon. Great for a good finish for us, but if you ever have to have paintwork or a repair done, it makes live a lot harder for the paintshop.
With either SRP or EDS, make sure you put a sealant / wax on top. That is what gives the protection / shine.