The MOMO wheel on the 99/00 is an airbag wheel. If it is fitted to your car I am pretty sure you legally have to have it operational which involves alot of headaches for fuck all benefit.
Your car is an MY98 and was not factory fitted with an airbag which leaves you free to fit an aftermarket wheel if you wish. If your car was factory fitted with an airbag and you remove it then there is issues with insurance etc but not in your case.