As far as easy to install goes extrembronco, they all "should" be the same. I say "should" because even though it's an industry standard lamp size, there are still a couple of brands out there that don't fit easily (depth-wise) without some cursing. I can't remember which brands though. I seem to remember that one of the cheapy brands gave one of the members here a hard time when he went to install them, but most of the others (myself included) have not had any issues with the install. A little surprise down the road with the old headlight switch and wiring in some cases, but for the most part it's a slam-dunk.
I've personally tried several brands in mine and had no fit problems.
Try doing a search for this subject and sift through all the reports and see if you can find the pros and cons.
And stay tuned to the mass-buy that Skuzzlebutt linked to as it should be coming about sometime soon (picture 50 people knocking on wood! lol) and is a decent price on a premier brand. There ARE less expensive lights out there for sure, but not all are of good quality or good light patterns which seems to be the main selecting point when choosing one of these setups.
Another good choice now for a decent price with a seemingly high quality product is the Delta brand at BC Broncos. They're not the cheapest either, but he's been using them now for a few months and is happy with them. I haven't tried them myself, but the reports are good.
Good luck with the search. There's been mucho discussion about them in the past.
Paul