OP - If I were trying to clone Jever I'd definitely use the Jever boiled water profile for starters. I'd use all pils (or maybe pils plus some chit malt) and I'd target ~ 44 IBU, with ~ 60% of the IBU (ie., around 25 IBU) added @ 60 min and spread the remaining balance of the IBU in 20 to 0 minute additions of Mittelfrueh or your German hops of choice. I'd step mash preferably, though you could mash 148F/90 mins in a pinch. I'd probably use Wyeast 2124. That would be roughly in the ballpark.