Less than 2 second align time is almost impossible to catch because of server ticks.
If you dont warp straight to gates (smartbombers) you should be fine.
I would choose blockade runner because if you fly it right can be pretty much unstoppable in low sec. You shouldn’t need WCS anyway.
The Sunesis might have a good align time but that is countered by large sig radius. I have caught them pretty easy with a fast locker that couldn’t catch ceptors with the same align time.
Blockade Runners are hard to catch too due to the high warp speeds. No one will be chasing you.
You can fit hyperspatial rigs too if you’re flying a lot and really cut down on your travel times.
A small tank on a BR is also easy to fit and will let you survive smartbombs. But you might not even need it because you warp cloaked, so smartbombers can’t see you landing.
I have killed cloaked blockade runners with smartbombs. Although you can’t see them landing, if you have eyes on when they enter warp, you can gauge their warp speed and the timing of when they should land. You then suddenly see a wreck appear next to you if you are correct :). So I would still recommend pinging off of a celestial or bookmark at a wide enough angle from the straight gate-to-gate route.
The BR is still better than Sunesis though due to being able to warp cloaked, having more situational fitting options available, etc. You can also just get a blops pilot/alt to bridge you to the edge of lowsec as well.
If you can afford mid-grade nomads, a hecate can align and warp in under a second and carry that much with a single cargo extension low/rig and fit enough tank to handle smartbombing battleships.
the Sunesis is better if you’re only moving 500m3 in lowsec, because instawarp is almost impossible to catch. The Blockade Runner is more expensive, depends on covops instead of instawarp (sucks if you cant cloak cuz of ■■■■ on the gate), and in general are only better when you need more cargo than that.