Firstly, a very good and plausible design; trully an alternative Type 12, with some significant improvements - the full sized Sea King, the 5-in gun, and still with Ikara; also, it could be reworked into an air defence destroyer on this common hull - yep, I really like this one
Re the Ikara, I would agree to go with the same set up as the Type 12's.
p.s. I'd also drop down the Seacat a deck, just to help with balance and accessability