My suggestion would be to make a simple semi-automated obsidian generator and turn the obsidian into gravel. Take the auto sieve from the quest and slap two stirling generators on it. Methacrylate is a great fuel source for them, a stack lasts forever. Use a hopper or item node to extract the products from the sieve into a Special Chest (from Router Reborn I think) with a packager upgrade and put on top of the sieve a barrel with hopper upgrade. Now all you have to do is to load the barrel up with gravel and take the Ore Gravels out of the chest. Add a second and maybe a third sieve, a couple more generators and the resources will come in at a rather nice pace.
To get the iron for this, do the quests for the Progressive Automation upgrades all the way down to diamond. Decompose the quest rewards for about 2 stacks of iron ingots. No grinding necessary.
I had the automation setup using - 2 auto sieves, a auto obsidian gen, 2 decomposers, and a Synthesis Machine, 14 Stirling generators, a Auto Crafter tier 3, a auto hammer, a furnace, and a router system with barrels from jabba.
How the setup working was quite complex (i think)
First i had a cobble gen setup to make cobble, instead of using a transfer pipe with a world interaction upgrade, i used a block breaker, that fed into a jabba barrel, then from there a transfer pipe would pipe in into 6 crucibles that had lava under them. as the crucible produced lava i pipe that into tanks for storage, from there i pipe some lava into the i think ender io tank (uses iron bars in the recipe). once all my tanks were full of lava, i would proceed to drop 1-4 empty buckets into the ender io tank, which would then fill them with lava and transfer them to a dispenser, which would dispense it and turn it to obsidian, which would then be immediately broken by another block breaker, and stored in another barrel. from there the obsidian would be pumped into a decomposer, then to a Synthesis Machine, and then into a chest, then a barrel (chest was there to make it so i could still use it without losing items). from the barrel it would go into two auto sieves. once sieved the items would be sent to the router, besides iron which would be sent to a auto crafter, with would make it into gravel, send it to the crusher, and so forth till it became dust, at which point it would be sent to a furnace to be smelt, and sent to the router to be sorted to its barrel.
this was all powered by a decomposer with a world interaction upgrade to decompose water into H2 0, the 0 would be sent to a trash can, and the H would be sent to a barrel for storage and later usage.
Later however i changed it to a setup that used double compressed cobblestone, a decomposer, and a Synthesis Machine, which made more Iron faster, but had WAY more byproduct, had to upgrade my O barrel to nearly a tier 3 with a larger storage upgrade, currently has over 500 stacks of 0