L450, EQT and L500 bolt up and use stock lines, and UM would be happy to tune any of them. With port injection and flex fuel you should see killer power, especially from the EQT and L500.
The LM500 is not one I've done much research on. I tried to at one point but the limited info I could find was in German. Price point is well above these two also. Only speculation here, but if it's using the same hot side, I can't imagine there's a huge variance in compressor compared with EQT and the L500.
You can do the EQT pre-order for $1845 shippped with the muffler delete and charge pipes. I'm not sure it makes any sense to pay $3200 for the German version which has no US distribution or support in the US, and probably is very close power wise. Unless someone has more info on this turbo that changes the equation...