These guys do bolt on Excel Kits, but the guy there Dave took me for a drive in a Lantra that he had put a T28 in and it was quite nasty :-)

He was willing to convert my Tib to F/I with a T28 for around $5,000 (Australian). This was intercooled, larger injectors, not sure about brands etc.

http://www.chiptorque.com.au/

Just thought I would add another potential kit to the 'pile'.