Well, the compiling tools and FGD files are basically the same for both Sledge and VHE. But if don't have any tools/fgd files at all, then here's the link to the compiling tools:
VHLT v33I'll try to find the fgd files later. Try looking for them in your "valve"/"cstrike" folders.
EDIT:
A CS 1.6 fgd fileFailed to find a fgd file for HL maps, but there's something you can still do:
-You can download Jackhammer (J.A.C.K.), which contains a HL fgd file (and the latest version of the VHLT compilers as well)
-If you don't or can't download jackhammer, you can try copypasting
this into a .txt file and then changing ".txt" to ".fgd".