Ok, first, I think you are right to consider not using any flavor or aroma hops because they are likely to disappear pretty quickly. But, I only offer that advice if you plan on cellaring the barleywine for a few years. I've had some pretty tasty barleywines that were only a few months old that had great hop presence. They were still slightly hot, but it went well with the rest of the beer.
I think it's all about what you expect from the beer. I had a Belgian Golden Strong Ale that I messed up the hops and added twice the bittering hops. At bottling it was very bitter, but after a few years it got carbed up and the bitterness dropped out and I think it was really pretty good (But more like a Belgian barleywine than a BGSA. I hope this latest batch is drier...) Your recipe is on the high end for a barleywine in gravity, and if you want to make an English barleywine, then you need to hop it accordingly, by which I mean enough to support the malt for at least a while, but I think you really want to avoid using late hops or making the beer all about the hops.
If you wanted to make this an American Barleywine, then more late hops and even more bittering hops would be fine. I'm not sure how late hop compounds react in beer over time. If this is going to be kept for a few years, those hop compounds might degrade into something less than enjoyable. Or it will be fine, I don't know. Simcoe would be fine for either an English bittering only, or an American for late hopping.
Really you could use any hop variety, but a high alpha hop would be better for bittering as you would use less and have less chance of vegetable flavors in the beer. Plus they are less expensive and there won't be as much in the kettle to deal with (if that's a problem for you.)
I would say maybe 2 ounces Simcoe for bittering an English Barleywine, and 3 ounces for an American. Or maybe go 2 ounces Simcoe for bittering, and 2 ounces Centennial at 20 minutes.
Again, I think it depends on what you want to do, make a sweeter, thick and rich English barleywine with raisin, toffee, etc., or go American, with more hope presence with less of the sweet fruit and caramel flavors.
This is a good topic and I think you'll get a variety of responses.
