Ask around in your area for exhaust manufacturers, maybe you can get a similar design like the slk32 amg or some other style you would like. Or look for brand new/used slk 32 in the web, mercedes stores or the scrapyards in your area.
Also when I was in the uk, guys in the shop "carnoisseur" was helpful, maybe you can ask them to source this part for you.
I was lucky, and got three stickers with my exhaust.
I can't even begin to work out how much power that liberated, but it must be almost 1000 (10^3).
Where can I get more of these stickers?
Does a clear-bra have the same effect?
You asked for tips;
First one is don't ask a question when people are in a flippant mood!
Second is that the SLK32 is a V6, so will have a different exhaust; I realise you only want the tips to match.
There are many routes top this; depends on the alignment of your existing tip in the slot.
Mine has the existing tip to one side, so I would have to re-make the back-box assembly to get a different tip.
You may be lucky, and have your existing tip in the centre, in which case you can bolt on an after-market goodie. Or take off your pipe, and get a proper one welded on. Probably come to about 50 GBP.
The final one is to get a replacement back-box assembly; Powerflow would be 200 GBP for that, but I've heard stock is much cheaper (!)