help! st185, replace engine or swap to a 205?

im replacing the engine in my st185, i have 2 available to me, another 185 or a 205. The 205 is more money, 2250 compared to 1700 CAD but if there's good reason to spend the money i will. along with the new engine im putting in a kinugawa 60-1 bolt on turbocharger with manual controller and 3" turboback exhaust . in the near future i will also be adding larger injectors and a programmable ecu (haltech platinum 1000 with plug and play adaptor). the compression ratio on the 185 is 8.5:1 and the 205 is 8.8:1, different head? the intercooler is different as well, does the 205 w2a cooler need a heat exchanger? not sure how that system works, possibly going to fmic anyway. do all the coolant lines etc. match up? is there anything else i need to know about the swap to the 205?