89 golf cabby engine conversion

I own a 1989 golf cabby . I'm looking for an engine swap. Can anybody tell me best for performance must be with an autobox. I was considering vr6 but worried it's a heavy lump. Also can anyone recommend a garage to do conversion. Before everyone gets on my back about doing myself I'm working 12 hours days so no time. 

Where in this country are you based?

VR6 is a heavy lump and difficult to do, 1.8 20v turbo is a popular upgrade, 1.8 16v is an easy conversion as is fitting a 2.0 bottom end (out of Mk3 golf GTi) and keeping your old head or maybe a GTi cam popped to your old head for a little extra.

Alot depends on how much money you are looking to spend.

Ever thought about possibly buying a car which has already been converted but not sure I've seen many with an auto box, is the auto a must?