a wideband is a crazy good help at any mod level. you can get an AEM gauge like i have for ~$250 i think. i bought mine from someone else brand new but never used for $210 shipped. youd be surprised at how much easier it is to tune when you dont have to rely on the narrowband being accurate or consistant. it helps to be able to lean the car out correctly and get it running tip top as well.

nothing feels better than a car on the brink of being too lean. that is the fastest a car will ever be.