The 059 and 520 heads flow very similarly, increasing all the way to 0.500" lift. Can use the same Comp 787 retainer, 0.050" offset locks and LS beehive combination as the L31 head to gain lift capacity.
I would probably go with a Lingenfelter 74211 in that truck. It is the lightest truck that engine came in, you have a looser converter and decent gearing. Keep in mind if you go with those wheels, you will loose a lot of what the engine modifications will gain you from the additional weight. I am not a huge fan of a dual pattern cam in a 305, but not many single patterns exist that are EFI friendly in a 305 without a lot of tuning. The 74211 has a 211/219 @ 0.050 duration and it is on a 112 LSA. It will still make decent vacuum to keep your power brakes happy. With 20* more duration at 0.050" on the intake lobe, it will move the powerband up a fair bit but given your S10 converter should stall about 2,400 rpm behind a L30 if it is running well, it will jump right into the powerband quickly. The GM ZZ4 cam is also a very similar grind at 208/221 @ 0.050 on a 112 LSA and probably could not tell a difference between the two from the driver seat. The Summit 8801 is also right there in the mix spec wise and some seem to love those Summit branded cams. In a 305 I would get a Cloyes 9-1157 single roller chain with the 3 way adjustable crank sproket and advance the cam 4* with a cam of that size. 305 needs to close the intake valve a bit sooner than a 350 to keep its low-speed torque, but needs a fair chunk of duration to get decent flow through its smaller intake valves and smaller bores.