Especially if you like what the RY does for you the HD/EM set that Tim, and myself for that matter, is liking quite a bit would be a great idea I recon (though Tim of course knows this stuff better than any of us by factor 100 minimum =) ). The HD and RY complement each other very well. They both come from a similar place and have a similar goal, but approach it in different ways. A band where one guy plays a HD and one a RY should lock beautifully. The HD will give you more low end, growl, and warmth, opposed to the RY rocking scream, overtones, and punchy low end.
The Crawler also fits into that as the third one. There is a good reason why my four main guitars have the pickups they have. Got one with Crawler bridge MQ neck, one RY set, one with HD / EM, and one with the 10th set. The first three are like brothers. Same blood yet different, and the last one is kind of the father. Bit more layed back, but still same base DNA.