Well Achilles already gave a solid answer.
A big Titan sized walker is still within the scope of ViDE FuCo.
A Walker with the size of the Crusader should look like this:
Size: 5, Crit: 12+ Hit: 9+ Sv: 3+ Night Vision, Radio, Walker
SP: 5, Mv: Walker 6"
Points: 420All the options of the Heavy Combat Walker, P.120, the Frontal Armour Upgrade would be +80 points.