If your computer can run 128x Texture Packs... Sphax itself is 16x16 through to 512x512 but all the mods are 128x128. Sphax covers all mods except Character Adding mods (Tale Of Kingdoms, Millenaire, Mo' Creatures) And Xies Farming.... Everything else from forestry to railcraft etc. is all textured. But NOT on the default sphax thread. Ruyan And Amon and Caden and many others do a great job with the modded textures.
The Sphax Add-On Project also has a Pack for Tekkit SMP 1.1.4: http://www.eclipse-project.de/forum/viewtopic.php?f=19&t=346
Sphax: http://www.minecraftforum.net/topic/376784-16x-32x-64x-128x-256x-512xmc11-sphax-purebdcraft-211211/
Sphax Add-On Project: http://www.eclipse-project.de/forum/index.php?sid=7d11a92f31dd08876f9b977bfa916d2e