Sousza My Man,
I was not attempting to compare capabilities of Caravan and Porter. Apples and oranges. Your points about IFR capability, etc. are correct, but the real question remains just what would a Caravan do for the IAC? Great aircraft with lots of utility, but what would it really do? General utility within IRE, NI, UK? Fair enough, but not much beyond - limited range and dreadfully slow. How often? Weekly at best is my guess. Visual Surveillance? Of what, with what type of profile? Low and slow? A bit big for that. Strictly visual - not the best visibility - or with sensors? Not required. How often? Once a month at best. Sounds like an EC-135 (or PC-6) role to me. Parachute training? Not the right platform for military airborne ops. Only practical for free fall, not static line. Jumpers could not stand in the cabin. Limited internal space for fully-equipped jumpers. Get an airlifter to do airborne ops properly.
I'm not saying the IAC should not get a Caravan, but let's be realistic about what it can and cannot do and what it will do.
I'm not sure what you mean by a light twin? Example please. I don't know of any light turbine twins, and certainly no petrol burners, that have better performance than a B200. As for the B200 - I'm saying pick up a used, low time model for no more than USD2M and fly it for another 15 years. Principal role = multi-engine training and general utility, meaning operating throughout IRE, NI, UK and into Europe for non-MATS, such as EU Battlegroup planning & coordination meetings and training and exercise support. No problem with range and performance for trekking to Finland, for instance, the furthest likely battlegroup partner nation. As for ME training, King Air variants are the platform of choice for every major western country, inlcuding the UK, US, Canada, Australia, NZ, etc.
A newer used B200 will do most of the missions you propose for a Caravan, with the remainder parsed out to the helo force, principally the 135's, with an occasional 139 utility mission. The IAC needs to grow out of its previous mindset as a type of offical Irish Flying Club and focus on core functions - training, MPA, deployable battlefield helos, airlift, national agency support (air ambulance, environment, inland SAR, crisis response, etc.) and MATS.