From the uses you are describing you will be fine with the D44 for 35's. As for the rear, guy could search for a semi-floating 14 bolt with the 9 1/2" ring gear with the 6 lug pattern. Check the bone yards for early 90's heavy 1/2 and light duty 3/4 ton Chevy's and GMC's.
As for gears, there is lots to factor: what motor do you have and how is it built? What trans do you have? Stick/auto? Overdrive?
A near stock small block will necessitate 4:56's. More torque, especially if you have a big block and you can use 4:11's. I'm guessing this is a stock 1:1 tranny so a guy would probably stick to 4:11's to keep the rpm's down on the highway but you won't come out the hole as easy with a heavy load.
There's lots to think about to get the combo happy together.
