eps installation is very simple.. what needs to be done is that your steering column(from the steering wheel to the cross) is removed and the other column with the eps kit on it is installed.. and after that just a pulse wiring is done from the distributor of the car to the ECU of the EPS so that it can sense the speed of the car and provide assistance accordingly..
And about the tyres, i have Michlen 165/65/13 on my ride, they are soft and grip is awesome.. you can go for them in 165/70/12 or yokohama s505 in 165/70/12 is also a gud tyre. i was having them previously..