The 3s isn't that great. I know I've done just about everything you can do. The stock ecu is garbage and full stand alone aren't reliable with them. Its an old design engine. Now the e153 trans is super stout so that will stay. A K20 is a badass engine that can with stand 400-500 whp easily with a budget turbo kit
And yeah I'll probably sell it after I drive it for awhile. When the numbers make sense they go. I do not enjoy driving my cars. I enjoy wrenching and building them. I spent two years on a build fully stripped down and built up and sold it 6 weeks after.