I've cooled somewhat on the idea of upgrades, unless you're absolutely are in love with an engine. I don't have the time to attempt upgrades myself. And if, when you're done, it doesn't work, then what? How much more time are you going to throw at it?
If I had an upgrade done, I'd have an experienced person do it (and remember that will include shipping costs in many cases). But when you run the numbers, given the cost of materials and labor, you have to start with an engine you almost got for free to make it work financially. Although I might mess with a ERR upgrade myself sometime, just to try it, I wouldn't ever attempt a PS3 upgrade.
In most cases, I've found you're better off getting an engine in the secondary market, with everything already installed and ready to go. If it has a problem, just send it off to a qualified person to repair. That seems to be a more cost-effective choice than starting from scratch with the purchase of an engine, and then purchaseing an aftermarket command, cruise and sound system, and then paying to have it all installed.