Thanks neilo. I see what your saying now. No, at the moment we buy in Suffolk mules and then put them to mainly texels.Are you keeping Texel cross ewes? I would suggest that your biggest benefit will come from increasing the worm resistance in your ewe flock, which of course is inherited by your lambs too.
For maternal Texels, there would be Innovis (AberTex) , Peter Baber and @easyram1 (I assume he is selecting for FEC ebvs). There will, no doubt, be others.
If you're thinking of more terminal sire Texels, I wouldn't know where to start.