TIme.
More time.
A lot more time.
Creating a new breed is a multi-year project that costs a bundle no matter how much you try to keep costs under control.
I'm 8 years into a project introgressing the blue egg gene into a Silver Laced Wyandotte phenotype. On the surface, you would think you could bring in just one gene with little or no problems. That is not the way genetics work. First I need the oocyanin gene on chromosome 1. Then I need the rose comb allele on chromosome 7. Then I need pattern, melanotic, and columbian on top of standard black/white/silver of the SLW line. Then I have to turn off the porphryin genes so the eggs are blue, not green. Then I have to select out the partridge gene because it mucks up SLW feather type. Why am I pointing this out? You are trying to bring multiple parent lines into the mix and have no idea the effects each parent will have on the offspring. Always be enthusiastic in anything you do, but do due diligence to understand just how many years of work you are tackling. Creating a new breed involving 4 or more parents will take a minimum of 12 years and could take 20 to 30 years.