First thing you should do is buy a race tech bible on suspension ,and learn as much as you can so you can do the work yourself,it will save you $ in the long run and is satisfying as well.It depends on how much money you want to spend ,i would start of with a set of gold valves ,the correct set of springs for your weight and go from there .If you want more you can put later model forks on ,but will need to be set up again to suit as well ,plus you have to get them to fit your triple clamps and other mods ,depending on what model forks you get.etc?How much do you wanna spend ,the sky the limit?You can get dlc coating lower sliders as well or they can repair the ones you have,you have to work out a budget ,on how much you wanna spend,ring a few suspension guys and see what they say ,get a few prices,they can be expensive.If your going to be in mx bikes for a long time ,and most of us are.i would do the first thing,buy a few tools and go for it ,most of the guys on this site do there own work and modifications and love doing it,that what it all about.