Any two part epoxy resin will work fine.
I like to use a 'medium' time setting one since my first go set to quickly and was a horrible grey colour so i also now use clear. This has the advantage of filling any small nicks or soaking into leather spacers and up the sides to fill the grove either side of the blade (as you look down onto it) and making them dark which is nice and neat.
Also a little tip i started to do - when you fit your handle (one part or several pieces together) you will push the glue back up through the hole for the tang - this is a good thing to get a good fit but it can stick to the blade, which can be difficult to get off withut causing scratches. If you put a little vasalene on the blade part where you dont want it to stick you can let it go quite tacky and just peel it off without worying about it getting stuck on the blade!
Makes it much cleaner.
Appart from that have a go its suprisingly easy and dont be afraid to use rough rasps and files to shape it.