The speedloader for a Smith J frame will work with your 605. I have 2 of them for my M85, along with a couple of speedstrips as another option.
The closest revolver would be the M94 series. They are available in blued or stainless with barrels from 2" to 5". The only thing really different is that the 94's have adjustable rear sights and the 2" models have a red plastic insert in the front sight.
I will say, based on mine and a couple of reviews that I read, the trigger will be much heavier than your 605. There is a world of difference between my M85 and my M94. But, after practicing with that heavy pull, my M85 becomes even more sweet. And yes, I do like mine.
I have been looking for some "Extras" for my 605 as well. I really desire a wallet holster, I want to be able to put it in my pocket. (front or back) But it seems they are hard to come by. What do you gents use? Any suggestions?