both na and turbo srt block are cast. the srt block has a oil return for the turbo. uses a more common crank pattern if you plan on going a full on standalone. both block are almost the same. you can use all the same internal parts in either engine. the cylinder heads are different. as the old na 2.4 use a head more common to the 2.0. later heads flow better with a new port designs. if it was me i would use a srt block do to being able to make it look cleaner plus i like the idea of using aem over a factory computer. the older block you can use a megasquirt but there are no more options as far turning unless you build a crank trigger system.
