I am a little confused here. You say you want a rough idle and more low end power. Why is it you want an engine that has a rough idle
For some strange reason, some people identify an engine that idles poorly with an engine that is very powerful, when in fact, the majority of engines that idle very rough are either tuned very poorly or are idleing so slow they ain't even making oil pressure.
You said that you want a cam that makes great low end power ... Well, in most cases, just changing to high performance cams in a basically stock motor will increase high RPM horse power at the expense of a loss of low RPM torque. In other words, long duration / high lift cams just raise the power curve up the RPM band. So much for your big increase in low RPM power!
You make no mention of wanting high HP at high revs. Well, that's exactly what a "big" cam is going to do in a stock motor. It's usually a trade-off ... Higher HP at high revs at the expense
on low RPM torque.
But don't give up yet ... You have a slight advantage here. You have a 05 XL1200. These new engines already have the Buell XB heads that breath very good without lots of modifications.
If you install a set of Andrews N4 cams, your stock heads can handle the better breathing (ie: volumetric efficiency) that these cams will provide. I would bet you will not give up any low RPM torque for high RPM HP. I would not select the Andrews N2 cams because they won't offer you any more power than the stock "W" grind cams you already have.
You can also get a good power increase with the SE .551" cams that are offered by H-D, but these cams seem to be very noisy. In fact, I just shit-canned a set of these that were in my motor. Couldn't stand the tapping sound it made at idle.
Do yourself a favor, and don't get all hung up on a "lopey" idling engine. If you install a set of 'big cams" that indeed give you a very lopey idle, the bike will run like shit unless you make many other internal modifications.
Don't make any mistakes you will regret later ... Go for the HP. and not the piss poor idle.