Welsh blacks are very hardy and self sufficient. I bought some Texel cross stores this year when I had run out of my own lambs and they were spot on, carcases were 22kg which surprised me
but downsize is that ewes have a lot of singles compared with my Lleyns which need careful feeding in the autumn to avoid too many multiple births.
Nothing wrong with crosses but with a small number I'd be tempted to breed pure.
I started with 10 4 and 5 year old Lleyns, sent 3 to market in January, one ten and two nine year olds and got £54.50 each which wasn't bad having had 4 crops of lambs out of them.
Good luck