Squats never had a Codex made for them, but they did have a full army list in the Warhammer 40K Compendium. They had plenty of support in their model range, and could field an entire army back in the day. They had ranges of metal and plastic kits for troops, plus heavy weapon teams, warlord and hearthguard retinue both in carapace and exo-armor, if I recall correctly, and bike and trike teams, also for regular and exo-armor. As far as vehicles go, they could only field Rhinos, I believe, but that's not really a mark against them, since at the time Eldar didn't have any tanks at all.