Your dual exhaust options are:Take out the crossover pipe and cap the one end and have an exhaust pipe bent up for the other side.
Ram horn exhaust manifolds...look great but expensive. www.ford-y-block.com or www.speedwaymotors.com
Headers (best performance)...various manufactures: Reds Headers, Sanderson, Patriot, Speedway Motors. I prefer Speedway Motors.
Your power steering options depend on a few factors but none are inexpensive. All options will be over $1000 or more.
There is ram assist which allows you to keep your stock column, steering box etc and if needed column shift
There is a conversion kit that uses a toyota steering box that requires cutting of column and or a new steering column....neither kit comes with power steering pump or brackets.
There is the option to put in mustang 2 type IFS with rack and pinion steering. This would still require pump and brackets.
See www.Midfifty.com for these kits. See www.ford-y-blocks.com for power steering brackets and pumps options.
Hope this helps!