SYE another question

OK, I'm going to have to have a SYE after I install my 5" lift. I'm looking at different SYE kits and I noticed something about electronic speedo connections. I have a 97 XJ Country model and am wondering which kit to buy. Do I need to be concernded about the speedo or is that a speed control cable that I'm looking at? I see that I can buy a RR unit for about $145 or go with a JB Convertions for arond $199. But, is the speedo a factor? I'm sure I have an electric speedo, so is this even a factor in what I'm thinking? I'm Serously looking at the JB set up. Seems I'm a bit confused with all the info the mfg. put out there and am sorry if I'm beating a dead horse but can't find the info I need. Thanks,
Ronaldo

All you have to do is use the drive gear and plug off the old tail housing. Shouldn't be a problem. The ones you are thinking of are a super short one that is completely electronic, no drive gears involved. Those won't do for you.