fit a LET, and sell your worked on XE.

Theres no point rebuilding your existing motor into a LET, as every single modification you've made to it is likely to be unsuitable for a turbo motor.

And theres no point fitting TB's etc, because after all said and done the LET will make a far nicer car to drive (given the nature of the car), than some screaming TB'd thing on aftermarket management, and will have more power out the box than you'll achieve with the other approach too, never mind once chipped/mapped.