As far as a 4x, those are both good Choices.. Just keep in mind parts availability and speed of getting those parts. When I bought my AE B5 and SC10.2 I bought 2 of each. 1 for parts and one to build to make sure I had all the spares. Plus I hit up ebay every day to see if I can scoop up a deal..
-----Its Only Exciting When in it comes down to a Fraction of a second!!!!