If you just bought say the andreani kit ( make sure its the correct one) that would be around 500 quid, plus say 50 quid for oil, another 60 quid for seals, let alone the time and hassle and tools needed to do the job... if you got a pair of monster 1200 online you are then at what yokes, mudguard, spacers, spindle, TC pick up....
Looks like it will be forks out and sent up to Maxton, they will rebuild with cartridge kit and springs to suit and return for £600, they also offer a rear shock and spring built to suit at £400ish so I think this looks the best option instead of cutting and shutting something from something else
Spoke to Richard at Maxton and he is making a custom set of GP20 cartridges and an NR30 rear shock for the Monster, he is also selecting the correct springs for both forks and shock to suit my weight. Should all be ready in a couple of weeks, then ship the fork legs for Maxton to fit the cartridges and then return for a quick refit. Will let you know how they perform once fitted
Well forks and new rear shock have arrived back from Richard at Maxton, very impressed with the service and quality of the parts, looks like a night in the garage tonight to refit, hopefully the weather will be dry over the weekend to give the new suspension a test