Can anyone help with the difference between the Fuji TKLAG and TKTAG guides please? I'm looking to build a light spin rod and was going to use the TKLAG for the first three guides and I'm contemplating changing to the TKTAGs for the rest?

TKLAG - Tangle free spinning guides
TKTAG. - Single foot running guides

You would be better off using the TKLAG-H guides for your first three and then the TKTAG running guides to the tip, all the same size.

KLs are used as reduction guides, KTs as running guides ... the ones you mentioned are both Alconite ring with Titanium frame. Check out KBs (TKBAG) for the belly section (i.e. in between the KLs and the KTs). These are important if you're using small guides in the belly section especially with the KR concept positioning. They are more powerful than the KTs, so ideally you would put some KBs in the middle and continue with KTs up to the tip.

Awesome thanks guys that's a great help.

On a light spinning rods I don't recommend using the belly guides. You could do a 16-8-5.5 then run 4 or 4.5's to the tip. I've done dozens of rods that way with very good results. Also I've done many using just the sz 16 high frame then the 5.5 high frame then sz 4.5 runners. It works as well as the three guide set up