I couldn't find a specifics on gapping spark plugs on the gstwins wiki, so what should i gap them to?

NGK Iridium plugs should come pre-gapped, and theyre believed to be one of the better plugs to use.

DPR8EIX-9

sorry i dont actually have the answer to your question though. xD

I believe .8mm to 1.0 mm is the correct gap.

NGK says .035" all years.  Suzuki 97 GS OM says .8-.9 mm (.031-.035").

The Suzuki OM (K9) also says to replace them every 7500 miles (12,000km)

It also suggest the following plugs

NKG DPR8EA-9 as the standard plug. DPR78 if the plugs gets wet and DPR9 if it gets hot.

DENSO X24EPR-U9 for their standard. 22 wet and 27 hot.

Michael