Difference in Body shells?

Should be starting my golf series 1 1.8t Soon when i can find a base car to start it on....Is there any difference between the 1.1 and the gti shells strength wise? What would be the best option for me?

There shouldn't be any strength differences between the the two shells your talking about, but one problem you will encounter is that the drivers side engine mount point is different on the small block shells and will need to be moved if you want to put a 20V in.

There's a guide on here how to do it tho. (it means cutting it off and welding back on!)

only real difference is low spec mk1 have extra brackets welded between bulkhead and chassis legs at bottom, plus moutn as above. over the years the washer bottle changed sides in the engine bay, and gti based cars have extra bracket for the metering head & airbox.  apart from that, all same. non-gti dont ahve roll bars, wishbones may need changing for ones with holes in and rear beam may not have holes for the arb either.