The one at Bestbuy is probably more than you need and the $ is a bit high.
Both Ebay and places like Crutchfield.com have several options that work great for the keyless entry install. You just tap into the blue/gree/yellow wires at the vac pump and the install is easy. Try looking around for a basic keyless module. Unless you think you really need an "alarm", you can use a $60 or less keyless module and it is fast and easy. Look at this for an example...
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=260191986576&ssPageName=STRK:MEWA:IT&ih=016
I used one just like this on my 16v and it works great.