Keep the R7's or go with G10's.
I rented the R7's for a day. I thought they were very good, but just lacked length. The ball flight of the tour preferred irons is pretty low, which is not good on BPB where a lot of the greens are elevated.
Some prefer the taylormades at St. Andrews in order to make the wind less of a factor. Their low ball flight sets up well for a links style course where you are often better off hitting it low. You can be more consistent on a hole like #17 for example, where us g10 players are totally screwed by a heavy left to right wind there. However, on #8 I am always rubbing my palms in Matchplay if the pin is in the front location and my opponent is playing Taylormades. The tour preferred and burners just can't handle that front pin well it seems.
Whichever way you go it will be a big adjustment. The rental option is great, it may seem like a waste of some hard earned cr. but the assurance that you got the right clubs for your game is worth it.