I'd check out the stock pickups on the 2005 RG321 because I think they are pretty good. The stock bridge pickup has pretty good clarity and it gives the guitar a very distinctive tone with the mahogany body. I might consider changing the neck pickup, though. Since you had a Gibson then I'm guessing that your pickups are normal spaced and you "should" put F-spaced pickups in Fender-esque guitars like Ibanez so that the strings line up with the pole pieces. That being the case, I would go ahead and sell the gibson as is and get as much as you can for it (which should be MORE THAN ENOUGH to buy a brand new RG321 and maybe even a new set of pickups).