Driveshaft questions

Here's the deal, 01 XJ with a RE 5.5 short arm, 231 with a hack n tap and a stock D35. I just installed the lift and the HnT and I'm in need of a rear shaft.

I did search and it gave me just enough info to be dangerous. I'm interested in doing the front to rear conversion with a spicer flat flange adapter. Is it really that simple?? Oh yes I'm in england so yard parts a 3 times as expensive and hard to find.

I'm at work at the minute so does anyone know the stock front length?? My rear is 34" on the money from flange to center of Ujoint.

Thanks