MK1 1.8TMK4 suspension conversion

i'm new here and would like to ask a question..

i recently done engine conversion of my MK1 with MK4 1.8T. since i live in Indonesia and it's really hard to find conversion parts, i decided to put an MK4 1.8T engine complete with MK4 front chassis (from front bumper till firewall) and married it with the original chassis of an MK1. i'm now about to run the engine, but i haven't figured the suspension configuration. i mean, the weight of the car might have changed a lot and need suggestion what kind of suspension configuration i should run?

thanks a lot