Hi leo, you can fit a 16.5 or 17 in the front doors without cutting, the 17 will need self tappers and you do need to wiggle them in but no cutting is needed mate, sony exsplodes will fit straight in if you get the 16.5
With the rear you can fit a 16 or a wee bit smaller, but you can also fit 6x5 and if you want you can fit 6x9 but will need to make a coller out of mdf so they hide under your original grills ( thieving B*****ds cant see them then lol)