Gah, if these superpowered ships were available, the GTVA wouldn't have been annihilated.
Frankly, given the scenario, I'd choose a Deimos class corvette modified to have a greater speed and jump recharge rate. It's also to have several wings of fighters (no bombers, we're trying to survive and run), the most the corvette can carry and supply. Most of the anti-capital ship beams except for one will be removed to make more room for material storage, processing and manufacturing so that it would be possible to replenish parts. And add the ramscoop for gas-mining if possible.
Battle tactic. Fighters provide a screen while the corvette hightails it out and then the fighters jump out.
Additional technology. The inverse of the subspace tracker. If an enemy capital is detected to be making a jump at nearly the same time, we check their subspace "frequency" and make sure to last minute change ours so that they don't jump us in subspace. The fighter screen can take out bombers so that's not a problem.