Personally, I don't think any car that wasn't designed out of the factory with DRL's looks 'right' with aftermarket ones. Some of the DIY efforts you see on cars are laughable, especially as the LED strips probably from eBay that are nowhere near the brightness of factory Cree LED setups and just look terrible, especially when a couple of the bulbs blow.
It doesn't make it look more modern in my view, just looks wrong. You need to consider the MOT as well and ensure that any mods don't break construction and use regs.
If you're going to do it, changing the fogs out for DRL's from a car that has similar size ones seems the best way to do it, and wire them into a switched live or similar. I think one of the recent Mondeo's had fog style DRL's, but I think hella are doing a few aftermarket units now too. I would definitely not go cheap on whatever you get, they just aren't bright enough.
However, it will still just look like you're driving around with your fog lights on... The facelift lights are nice on the A3/S3 and just look right, but then I'm a fan of originality, and each to their own and all that.