No need to go to the dealer. You can program the remotes at your house. I don't know what remotes will work with what vehicles. I know when I had my 98 I used an Explorer remote. I hated it because it had the blue trunk button on it. If you hop on eBay you can pick up 3 button remotes for fairly cheap. I got a used Ranger remote for $7 shipped to my door.
The only thing i suggest is that if you only have one key is to buy at least "one" more chip key. As long as you have two working keys you can program the spares at your house too and not have to pay for a locksmith/dealer to program them for me. When i bought my truck i only had one key and bought another one. When i went to get the spare programed there where 5 other keys programmed to the truck so he cleared them for me and only add the two i have.
2001 XLT 4x4 3.0 Fleetside Conversion
AC Mod, Turn Signal Mod, 265/70/16 AT2s on Chrome AR Chambers, SS Headlight & Fogs, 06 Corners, 06 Tails, Mustang Dome Light, Auto-Dimming Rear View Mirror, Lighted Dual Visors, OHC