You'd be surprised what you can find when you start looking and find the right places to look. Red Sussex will be available to you. Not to forego anything just to obtain them, make sure they are up to standard and table bird inclination of that variety. Dorking will also be available if you look.
What you see in local ads is not what you want. You want the best stock you can possibly find. Stock that is and has been bred to the standard. You may have to travel some but I've a strong inclination they are in Ireland if you look hard. Don't settle for "oh this was easy or this is the breed but it's hatchery crap". Get good quality, standard bred, birds. If you go to another breed or variety that's fine but only do so if it's of excellent quality and is bred for table.
What you see in local ads is not what you want. You want the best stock you can possibly find. Stock that is and has been bred to the standard. You may have to travel some but I've a strong inclination they are in Ireland if you look hard. Don't settle for "oh this was easy or this is the breed but it's hatchery crap". Get good quality, standard bred, birds. If you go to another breed or variety that's fine but only do so if it's of excellent quality and is bred for table.