They are not complicated to replace. You'll want fresh washers and then it's just a bolt at each end. Bear in mind it'll all be full of oil though.
In terms of where from, Suzuki will sell you new items. I'd be wary of 2nd hand parts in this instance as if they've had some trauma in a crash they can burst a little while after (seen this previously).
I had a set made up by a company called Pirtek by taking the old lines along for them to use as a pattern, so anywhere that can make up hydraulic hoses should be able to help. If they ask about pressures, I think it has to handle a whopping 30psi or so (most of the hydraulic lines and fittings are rated to hundreds of psi).
Jambo
Edit:
This thread suggests Goodridge may do a kit