hi darryl
you might contact PRC and ask them ..
they are very knowledgeable about the gear they sell
and might be able to offer you some advice about the lens &c ..
I've used a 14" on 5x7 for head/shoulder portraits and a 10" on a 4x5
typically I use about a 20" for 11x14 portraits. ...
I don’t know 11x14. But a 10 3/4” lens on 8x10 is a wide angle, not ideal for portraits! I guess a normal lens for 11x14 would be 18”, so I would think to go a bit longer for portraits- like 24”. The LFPF forum would connect you with a lot of ULF shooters that could make better, and specific, recommendations.