As John says, the brake balance isn't good on the Europa in standard form although the later cars should be better with the wider rear shoes.
In standard form there's a lot of braking (70%-ish) from the front and in dry conditions, that's fine. On wet roads it's very easy to lock the fronts in an emergency stop which obviously isn't good. Increasing the capacity/power for the front calipers will make this worse, so I wouldn't advise that without a corresponding increase in the rear braking.
In any case, swapping to GT6 calipers (Type 16) isn't a simple upgrade. The calipers are considerably heavier and the bolt spacing is different so you also need the caliper mounting brackets to go with them. The new mounts move the caliper higher because the Type 16 caliper is designed for a larger 245mm disc (232mm is Europa OEM) so you'll need the discs as well. Finally the stub axles & hub bearings are larger although I don't know if this is essential to a caliper conversion.
The mod you've described is something that's done quite often on the 2 seat Elan and I've done exactly that with mine. But the braking system on the standard Elan is different with 232/254mm F/R rear discs and in theory it comes very close to locking the rears before the fronts. So in that instance improving the front power does make the car safer although there's many Elan owners who will claim that in doing so you are ruining the original brake balance. (you are, but for the better ! )
In summary, if you want extra braking power then look at the complete system upgrade which will probably mean rear discs as well to balance it out - it becomes expensive ! I'm not even sure I'd go for the type 16 caliper anyway these days, there are more modern options available and these allow vented discs. In terms of bang/$$ I reckon you get most from disc diameter increase rather than caliper piston diameter; I'm running the standard type 14 calipers on 266mm discs and that works well.
Brian
