welcome
I live in the same area, bsj7315. Search my old posts, and ones from RoninJoliet on this forum for some relevant information to scanning this area. You don't need digital unless you want to listen to Plainfield PD, Illinois State Police, etc on Starcom. Digital scanners and digital signals are pretty challenging, and you have just a few choices there.
Joliet, shorewood, channahon, bolingbrook, naperville, kendall county, will county, all can be heard on a conventional trunk tracker (non-digital). My 2055 is a good example of a 200 dollar unit to do that which you can buy at radioshack. Joliet is very active, and a lot of fun to listen to. If you're south of Caton Farm, Joliet PD West (dispatch 3) patrols the area, but there's a lot more action in Central and East usually. Frankly, now that I have gotten Plainfield PD to come in clearly on my 20-176 antenna this week, it's disappointing that there isn't much interesting action to listen to, but I've crossed the technological hurdle.
whatever you do, get the software and cable to program your new scanner. It's so worth the 50 bucks, as programming by hand is technically possible, but in my opinion, completely unrealistic in this area....we have so much good stuff to listen to. You'll also want a premium subscription to RR database so that you can get the data into your scanner easily.
Welcome!