You can easily buy all the bodykit to make your studio look like an ST. Front bumper, foglights, grilles. Sideskirts, rear bumper and inserts and spoiler.

I know plenty of people that have done this and you wouldn't be able to tell from the outside. Then obviously lowering and ST alloy wheels which fit straight on. Seats if you want to as well. I know people that have made the full engine conversion from a 1.4 Zetec to the 2.0L duratec from an ST with gearbox, clocks, fuel pump and a couple of other things.