Maybe you could make a Valver grip as well as a Willy, but to make it handle as well youd need to basically fit Williams suspension (lot of bother) or be an expert in suspension set-ups to re-create the effect with off-the-shelf parts.
As it is, I dont think you can get Willy handling by lowering a Valver on coilovers as the Willy relies on the full suspension travel to give you what its best at (B-roads). Its much more controlled on, say, 50% of the suspension travel and reacts to input in a much friendlier way than my 16V did - both when it was standard and when it was lowered.
If youve got a good cashflow situation (can you tell Im a bean counter?) with lots of room to soak up some bills, then Id go for one of the cheaper Williams and do it up - giving you more money for that first insurance premium. Id say that the wheels will need refurbishing and bonnet/bumper/rear arches attended to whatever the price of the car (unless it was mine
). Youre going to have to do all that and more on a 16V in all likelihood too.