Who sells/likly to have in stock power steering hoses in braided type? Car is a 72 ElCamino 454

There's a company named "Gotta Show". Sold by most Street Rod parts vendors. They make hoses for anything. Just Goggle them and pick a vendor.

Buy the correct fittings...either flare seat or o-ring depending on the style of your steering box and make your own.
Easy!

Not sure I'd use braided on the high pressure line. We had a disaster here with a burst braided line on a hydraboost set-up. Shot hot PS fluid all over the engine compartment. Could have had a fire! What a mess!!

Hydraboost operates at higher pressure than an OEM PS configuration, but I would still use something heavier on the pump to gear box line. Mostly because I'm gun shy now, though.