Assuming that you want the rhubarb flavor to be the feature of this beer, I'd recommend you use only a neutral bittering hop to give the beer the amount of bittering you want or a little less as I think the rhubarb will be a little bitter by itself. I've used Nugget and Magnum but there are a number of others. Nugget and Magnum are high alpha acid hops which means it takes only a small amount to give the bittering. Others with lower alpha acid might be a better choice. I don't know that turning it into an NEIPA would work out to get the rhubarb flavor.