In reply to Jen Appleyard:
I'm thinking along the same lines as the wannabe goat... It's tricky, as soft shells come in many types, each really suited to a particular niche set of weather conditions and activity. It's bewildering, even for people buying for themselves, never mind buying for someone else... How water resistant? How warm? Pockets? Hood? Other features?
What does he normally wear when walking? Why do you think he wants a soft shell jacket?
If he's broad (assuming you mean broad shouldered), then I'm a bit surprised he's a Rab fan, as I find their clothing quite narrow shouldered. At least you ought to have a good idea of what size to buy him.
If he runs warm, then something with significant insulation is likely to be too warm for him, and lack versatility. In which case, something with less insulation might suit best; the Rab VR range, perhaps. Or, if you want rugged (why?), one of the uninsulated, 'heavyweight wind resistant' variants, such as the Rab Exodus. Note the weight; though; they're heavy.
If there's one piece of clothing that I'd recommend someone to buy, if they haven't already got one, it would be a lightweight windshirt; it makes for a very versatile layering system. It will be a lot cheaper (I'm sure that's not your concern, but you could spend the difference on other presents...), and much, much lighter than the likes of the Exodus. they seem flimsy, but they're surprisingly rugged. This thread, although a bit old, has my thoughts on versatile layering, and the place for the windshirt:
http://www.ukclimbing.com/forums/t.php?t=377801#x5471096
Apologies if I've pitched the advice incorrectly.
Make sure whatever you get, that he can return it if it's not what he's looking for, and make sure he knows you're happy for him to do that.