Both are rebuildable, you may want to investigate local companies that can do it and cost/service life. I would guess that Fox shocks would have a wider network of dealer/rebuilders.
Double check but I think for the fronts you want Bilstein AK7114SB06 Bilstein M 7100 Series Shocks | Summit Racing - https://www.summitracing.com/parts/bsn-ak7114sb06
and rears Bilstein AK7112SB06 Bilstein M 7100 Series Shocks | Summit Racing - https://www.summitracing.com/parts/bsn-ak7112sb06
Standard fuel line is capable of supporting gasoline, diesel, biodiesel, ethanol, and oil.
I don’t remember but did you use Walbro pickups in your new large tank? May want to if not.
picture from J Mack