2004 Ford F-150 Clutch

04 F150 Heritage 4X4, 4.2 V-6, 5 sp manual. Have recently had to begin adding fluid to clutch reservoir and noticed clutch chatter until vehicle is driven/warmed up. When level gets low, have excessive free play in clutch. Suspect slave cylinder is leaking as this seems common problem with this vehicle. Slave cyl is internal to bell housing and therefore must drop trans etc to repair. Question: are there any after market kits to convert this hydraulic clutch to mechanical linkage? Or, if I repair it, is there a fix to the existing slave to ensure it lasts longer than 53K miles before leaking. Finally, since the leaking fluid must be getting on the clutch disk to cause the chatter, should I go ahead and replace the entire clutch when it is apart? Thanks