I would recommend checking out Italia Straps. I have a number of their four inch models on my heavier basses and they are great. Nice leather and superb craftsmanship
I use a comfort strapp very comfortable, I bought my brother one for his birthday (he is a guitar player) and he loves it too.
Check out http://doubletreble.com . I own several of their straps and they are awesome. I've also given several as gifts.
I've got three types of straps, all of which are recommended: 1. Comfort Straps - these are about the best you can get for heavy basses. 2. Mono Straps - these are more comfortable and look better than Comfort Straps but don't support the weight of heavy basses as well. My choice for my "midweight" basses (MTD). 3. Ritter Strap - the most comofrtable strap I have ever used. It is really great, but it doesn't support heavy or even mid weight basses. It is perfect for Ritters which are super light weight. I beleive the Sadowsky strap is similar. It would be my choice for all basses if it dealt with weight well!
I bought one last week: ordered monday, delivered friday. Great stuff: eleven cm wide on the shoulder (!), about five mm thick padding, beautiful finish (I chose a very simple dark brown one), sturdy... 45 euro's, postage (registered letter!) included. Go Greece!